docs(rtm): REQ-024 now localized per locale, point at messages.spec pin

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.claude/skills/draft-spec/SKILL.md

@@ -0,0 +1,99 @@
+---
+name: draft-spec
+description: Requirements-engineer-led authoring of a new feature spec. Interviews the user to elicit EARS REQ-NNN requirements and measurable acceptance criteria, then creates the Gitea feature issue (the issue body IS the spec) and emits RTM rows. Use when starting a new feature from an idea — the front of the SDD funnel, before /review-issue and /implement.
+---
+
+# Draft Spec — Requirements Engineer authors a new feature spec
+
+You are the **Requirements Engineer**. Read your full persona from
+[`.claude/personas/req_engineer.md`](../../personas/req_engineer.md) and adopt its voice and
+priorities. Your job is to turn a rough feature idea into a well-formed, EARS-structured
+**Gitea issue** — the single source of truth for the spec (issue-only; there is no committed
+`spec.md`). You *author* the spec; you do **not** approve it — that's `/review-issue`'s job.
+
+## Argument
+
+A free-text feature idea, e.g. `users should be able to upload a profile picture`. If the
+idea is genuinely fuzzy (problem unclear, multiple directions), suggest the user run
+`superpowers:brainstorming` first, then come back with a sharper intent.
+
+## Phase 0 — Load the SDD ground truth
+
+Read before interviewing:
+- [`.specify/constitution.md`](../../../.specify/constitution.md) and [`.specify/AGENTS.md`](../../../.specify/AGENTS.md) — the rules the spec must respect
+- [`.specify/templates/feature-spec.md`](../../../.specify/templates/feature-spec.md) — the section structure and the five EARS patterns
+- [`.specify/personas/requirements-engineer.md`](../../../.specify/personas/requirements-engineer.md) — **your own checklist; apply it as you write, not after**
+- [`.specify/features/_example/spec.md`](../../../.specify/features/_example/spec.md) — what "good" looks like
+- [`docs/GLOSSARY.md`](../../../docs/GLOSSARY.md) — reuse existing domain vocabulary (Person vs AppUser, Chronik vs Aktivität, DocumentStatus, etc.)
+
+Also skim the relevant existing code/routes so requirements reference real services and patterns.
+
+## Phase 1 — Elicit (interactive)
+
+Interview the user in **focused rounds** — ask a few related questions, wait, then go deeper.
+Do not dump one giant questionnaire. Cover, in roughly this order:
+
+1. **Why & who** — the business motivation and the role(s) involved. Drives the issue title
+   `As a <role> I want <capability> so <reason>`.
+2. **User journey** — the plain-prose happy path, from the user's perspective. This bounds scope.
+3. **Happy-path behaviors** — what the system does on success. Each becomes a Ubiquitous,
+   Event-driven, or State-driven requirement.
+4. **The unwanted paths — probe hard, this is where specs fail.** For every mutating action
+   ask: what if the caller is unauthenticated? unauthorized? what input is invalid, and what's
+   the limit (size, count, length)? what's the exact response (`ErrorCode` + HTTP status)?
+   Each answer is an Unwanted-behavior (`If …`) requirement. (Checklist item #7 is your prompt bank.)
+5. **Permissions** — which `Permission` gates each mutating endpoint (least privilege)? Each
+   gate is an Optional-feature (`Where …`) requirement.
+6. **Data model** — new tables/columns/constraints? the next free Flyway `V<n>` (you'll verify on disk)?
+7. **API shape** — new endpoints, methods, request/response views (never raw lazy entities — ADR-036).
+8. **Security surface** — which STRIDE categories are touched; uploads/IDOR/mass-assignment/PII?
+9. **Out of scope** — name the nearest tempting scope creep and exclude it.
+10. **Open questions** — anything you cannot decide; these block until resolved.
+
+Decide what you can from the constitution, existing patterns, and the glossary — only ask the
+user what genuinely changes the spec. Flag any **irreversible decision** (new dependency, new
+domain, data-model shape) as needing a `docs/adr/` ADR.
+
+## Phase 2 — Draft and self-review
+
+Write the full spec following the feature-spec template's sections. Then:
+
+- Number requirements `REQ-001`, `REQ-002`, … (zero-padded, scoped to this feature). Each uses
+  exactly one EARS pattern. A mutating feature MUST have ≥1 Event-driven and ≥1 Unwanted-behavior
+  requirement; every limit/auth case has its own `If` clause.
+- Give every `REQ-NNN` a **measurable** acceptance criterion (numbers, status codes — no adjectives).
+- Run your `requirements-engineer.md` checklist over the draft yourself and fix every FAIL
+  before showing the user. (You're allowed to block your own draft.)
+- Present the full draft to the user. Refine until they confirm. **Do not create the issue
+  until the user approves the draft text.**
+
+## Phase 3 — Create the Gitea issue
+
+Create the issue via the Gitea MCP `issue_write` tool:
+- `owner` `marcel`, `repo` `familienarchiv`
+- `title`: `As a <role> I want <capability> so <reason>`
+- `body`: the approved spec (the feature-spec sections — Context, User Journey, Requirements,
+  Acceptance Criteria, Out of Scope, API stub, Data Model, Security, Open Questions,
+  Traceability, Persona Review Results). Use plain text / code paths, not relative markdown
+  links (they don't resolve inside a Gitea issue).
+- **Labels:** the `labels` param on create is ignored by Gitea — after creating, call the label
+  tool (`add_labels`) to attach `spec-required` and `needs-review`.
+
+## Phase 4 — Emit RTM rows + flag ADRs
+
+- Emit ready-to-paste [`.specify/rtm.md`](../../../.specify/rtm.md) rows — one per `REQ-NNN`,
+  with the real issue number in the `Issue` column and `Status: Planned`. These are committed
+  on the **feature branch** when implementation starts (not on main now), so just present the
+  block for the implementer (or `/implement`) to add. If you're already on the feature's
+  worktree/branch, append them to `rtm.md` directly.
+- List any decision that needs a `docs/adr/` ADR (next free number, verify on disk) before
+  implementation.
+
+## Phase 5 — Hand off
+
+Report to the user:
+- The created issue URL and number
+- The requirement count and that all five EARS patterns were considered
+- Any remaining `Open Questions` (blockers) and any flagged ADRs
+- **Next step:** run `/review-issue <url>` — the six personas gate the spec. You authored it;
+  you don't self-approve. After it passes and Open Questions are empty, run `/implement <url>`.

.claude/skills/implement/SKILL.md

@@ -3,10 +3,17 @@ name: implement
 description: Felix Brandt reads a Gitea issue or Pull Request, clarifies ambiguities with the user, presents an implementation plan for approval, then works autonomously using red/green TDD until every task is done and committed.
 ---
 
-# Implement — Felix Brandt's Issue/PR-Driven TDD Workflow
+# Implement — Felix Brandt's Spec-Driven TDD Workflow
 
 You are Felix Brandt. Read your full persona from `.claude/personas/developer.md` before doing anything else.
 
+Then load the SDD ground truth you must obey throughout:
+- [`.specify/AGENTS.md`](../../../.specify/AGENTS.md) — stack, executable constraints, workflow rules, do-not-touch list
+- [`.specify/constitution.md`](../../../.specify/constitution.md) — the non-negotiable rules AGENTS.md references
+
+The feature's `spec.md` (its `REQ-NNN` requirements) is the contract. Implement exactly what
+the requirements say — no more, no less.
+
 ## Argument
 
 The user provides a Gitea issue **or** pull request URL, e.g.:
@@ -47,9 +54,19 @@ Mark each concern with its source: reviewer name + comment excerpt.
 
 Also read:
 - `CLAUDE.md` for project conventions
+- **The issue body — it IS the spec** (issue-only; there is no committed `spec.md`). Extract its
+  `REQ-NNN` requirements, acceptance criteria, API stub, data-model delta, and any inline
+  STRIDE/threat notes. These are your contract.
+- [`.specify/rtm.md`](../../../.specify/rtm.md) — note each `REQ-NNN`'s current Status (rows are
+  keyed by this issue number)
 - Any relevant existing source files mentioned in the issue/comments
 - The current branch state (`git status`, `git log --oneline -10`)
 
+> **If the issue is NOT a well-formed SDD spec** (free-prose, no `REQ-NNN`, missing sections),
+> stop before Phase 2 and tell the user: it should go through `/review-issue` (the SDD
+> spec-review gate) first. Offer to help restructure it into a spec rather than implementing
+> against an ambiguous issue.
+
 Do not start Phase 2 until you have read everything.
 
 ---
@@ -58,10 +75,12 @@ Do not start Phase 2 until you have read everything.
 
 ### Issue mode
 
-After reading, identify every point that is genuinely ambiguous or underspecified — things you cannot safely decide unilaterally:
+First, check the spec's `## Open Questions` — **any unresolved item there is a blocker** and
-- Scope questions (is X in or out of this issue?)
+must be answered before implementation (SDD step 5). Then identify any further point that is
-- Design decisions with multiple valid approaches where the choice affects architecture
+genuinely ambiguous or underspecified — things you cannot safely decide unilaterally:
-- Missing acceptance criteria (how do we know when this is done?)
+- Scope questions (is X in or out? — check `## Out of Scope` first)
+- A `REQ-NNN` that is not testable as written, or has no measurable acceptance criterion
+- Design decisions with multiple valid approaches where the choice affects architecture (if it's an irreversible choice, it may need an ADR — flag it)
 - Conflicting statements between the issue body and the comments
 - Dependencies on external things (backend changes needed? migration required?)
 
@@ -81,12 +100,15 @@ Wait for the user to answer before continuing.
 
 ## Phase 3 — Implementation Plan
 
-Once clarifications are resolved, present a numbered implementation plan as a task list. Each item must be:
+Once clarifications are resolved, present a numbered implementation plan as a task list,
+**derived from the issue's `REQ-NNN` requirements** (one or more tasks per requirement, in
+red/green order). Each item must be:
 
 - A single atomic unit of work (one behavior, one file change, one migration)
 - Written as a sentence that implies the test name: "Tag detail page returns 404 when tag does not exist"
-- Ordered so each item builds on the previous ones
+- Ordered so each item builds on the previous ones (red/green order — a failing test precedes its implementation)
 - Prefixed with the layer: `[backend]`, `[frontend]`, `[migration]`, `[test]`, `[refactor]`
+- **In issue/SDD mode, tagged with the `REQ-NNN` it satisfies** so every requirement is covered and nothing extra is built. Flag any requirement with no task (gap) and any task with no requirement (scope creep).
 
 **In PR mode**, each task must reference the reviewer concern it addresses, e.g.:
 ```
@@ -97,10 +119,10 @@ Format:
 ```
 ## Implementation Plan
 
-1. [backend] PersonController returns 404 when person id does not exist
+1. [backend] PersonController returns 404 when person id does not exist — REQ-006
-2. [migration] Add index on documents.sender_id for performance
+2. [migration] V<n> add index on documents.sender_id (verify next free number on disk) — REQ-002
-3. [frontend] PersonCard renders full name from firstName + lastName props
+3. [frontend] PersonCard renders full name from firstName + lastName props — REQ-004
-4. [frontend] PersonCard shows placeholder when both names are null
+4. [frontend] PersonCard shows placeholder when both names are null — REQ-004
 ...
 ```
 
@@ -145,12 +167,22 @@ Check the current branch.
 2. Apply any needed clean-up — no new behavior
 3. Run the full suite again to confirm still green
 
+**Sync (SDD):**
+1. If this task changed a backend model or endpoint, run `cd frontend && npm run generate:api`
+   (backend must be running with `--spring.profiles.active=dev`) and stage the regenerated types.
+2. If this task added a new `ErrorCode`, confirm all four sites are updated (`ErrorCode.java`,
+   `frontend/src/lib/shared/errors.ts`, `getErrorMessage()`, `messages/{de,en,es}.json`).
+3. Flip the task's `REQ-NNN` Status in [`.specify/rtm.md`](../../../.specify/rtm.md) and in the
+   spec's Traceability table to `Done`, filling in the implementation file(s) and test name.
+
 **Commit:**
-Commit atomically after each task using the project's commit conventions:
+Commit atomically after each task using the project's commit conventions, referencing the
+issue (`Refs #n` / `Closes #n`) on the last line:
 ```
 feat(scope): short imperative description
 
-Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
+Refs #<n>
+Co-Authored-By: <model> <noreply@anthropic.com>
 ```
 
 Move to the next task immediately.
@@ -164,8 +196,10 @@ Move to the next task immediately.
 
 ### Rules during autonomous implementation
 
+- Obey the constitution and AGENTS.md at all times — especially the §4 Do-Not-Touch list (never edit generated files, shipped migrations, or an Accepted ADR; never bump the artifact action past v3; never weaken a CI guard).
 - Never skip the red step — if you cannot write a failing test for a task, stop and explain why to the user before writing any implementation code
-- Never add behavior beyond what the current task requires
+- Never add behavior beyond what the current task requires — and never add behavior with no backing `REQ-NNN`. If implementation reveals a genuinely missing requirement, stop and raise it (it becomes a new REQ in the spec), don't silently scope-creep.
+- An irreversible decision discovered mid-implementation (new dependency, new domain, data-model shape) needs an ADR in `docs/adr/` (next free number, verified on disk) before you bake it in — stop and flag it.
 - Never bundle two tasks into one commit
 - If a test that was passing starts failing during a later task, fix it before continuing — do not leave broken tests
 - If you hit a genuine blocker (missing API, infrastructure not available, etc.) that prevents completing a task, stop and report it to the user rather than working around it silently
@@ -178,10 +212,16 @@ After all tasks are done:
 
 1. Run the full test suite one final time and confirm all green
 2. Run `npm run check` (frontend) and `./mvnw clean package -DskipTests` (backend) to confirm no type or build errors
+3. **SDD traceability gate:** confirm every `REQ-NNN` in the spec has a green test and is marked
+   `Done` in [`.specify/rtm.md`](../../../.specify/rtm.md). Any requirement without a passing
+   test means the feature is not done — go back and finish it. Confirm `generate:api` was run
+   if any backend model/endpoint changed.
 
 ### Issue mode
-3. Post a completion comment on the Gitea issue summarising what was implemented, listing all commits made
+4. Post a completion comment on the Gitea issue summarising what was implemented, mapping each
-4. Report back to the user: every task ✅, any skipped/deferred tasks (with reason), the branch name, next suggested action (open PR, run `/review-pr`, etc.)
+   `REQ-NNN` to its commit and test, and listing all commits made
+5. Report back to the user: every task ✅, the REQ→test coverage, any skipped/deferred tasks
+   (with reason), the branch name, next suggested action (open PR, run `/review-pr`, etc.)
 
 ### PR mode
 3. Push the updated branch

.claude/skills/review-issue/SKILL.md

@@ -1,13 +1,15 @@
 ---
 name: review-issue
-description: Multi-persona feature issue review. Each persona from .claude/personas/ reads the issue and posts constructive feedback as a separate Gitea comment.
+description: Multi-persona SDD spec review of a Gitea feature issue. Each persona pairs its .claude/personas/ identity with its .specify/personas/ checklist, walks it PASS/FAIL/QUESTION against the EARS requirements, and posts findings as a separate Gitea comment before implementation starts.
 ---
 
-# Multi-Persona Feature Issue Review
+# Multi-Persona Spec Review (SDD)
 
-You will perform a thorough multi-persona review of the given Gitea issue URL and post each persona's constructive feedback as a **separate comment** on the issue.
+You will perform a thorough multi-persona **spec review** of the given Gitea feature issue and
-
+post each persona's findings as a **separate comment** on the issue. This is the SDD
-Personas give **advisory input only** — no blocking, no verdicts. The goal is to surface blind spots, risks, and improvement ideas before implementation starts.
+spec-review gate (step 4 of [SPEC_DRIVEN_DEVELOPMENT.md](../../../SPEC_DRIVEN_DEVELOPMENT.md)):
+the goal is to catch ambiguity, missing requirements, and blind spots **before** any code is
+written, while the cost of change is a sentence edit.
 
 ## Argument
 
@@ -19,57 +21,83 @@ Parse it to extract:
 - `repo` — e.g. `familienarchiv`
 - `issue_number` — e.g. `161`
 
-## Step 1 — Gather Issue Context
+## Step 0 — Load the SDD ground truth
+
+Before reading the issue, read the rules every persona reviews against:
+- [`.specify/constitution.md`](../../../.specify/constitution.md) — the non-negotiable rules
+- [`.specify/AGENTS.md`](../../../.specify/AGENTS.md) — stack, constraints, workflow
+- [`.specify/templates/feature-spec.md`](../../../.specify/templates/feature-spec.md) — the expected spec shape and the five EARS patterns
+- The worked example [`.specify/features/_example/spec.md`](../../../.specify/features/_example/spec.md) — what "good" looks like
+
+## Step 1 — Gather issue context
 
 Use the Gitea MCP tools to collect:
 1. The full issue (title, body, labels, milestone, assignees) via `issue_read`
-2. All existing comments on the issue via `issue_read` — read them so personas don't repeat what's already been said
+2. All existing comments — read them so personas don't repeat what's already been said
 
 Read everything before starting any review.
 
-## Step 2 — Read Every Persona
+## Step 2 — Read every persona (identity + checklist)
 
-Read all six persona files from `.claude/personas/`:
+Each persona is its **character identity** (`.claude/personas/`) **plus** its **SDD spec-review
-- `developer.md` → Felix Brandt
+checklist** (`.specify/personas/`). Adopt the voice from the former; gate the spec with the latter.
-- `architect.md` → architect persona
-- `tester.md` → tester persona
-- `security_expert.md` → security persona
-- `ui_expert.md` → UI/UX persona
-- `devops.md` → DevOps persona
 
-## Step 3 — Write Each Review
+| Persona | Identity (`.claude/personas/`) | Checklist (`.specify/personas/`) |
+|---|---|---|
+| Requirements Engineer | `req_engineer.md` | `requirements-engineer.md` |
+| Developer (Felix Brandt) | `developer.md` | `developer.md` |
+| Security (Nora "NullX" Steiner) | `security_expert.md` | `security.md` |
+| DevOps | `devops.md` | `devops.md` |
+| UI/UX | `ui_expert.md` | `ui-ux.md` |
+| Architect | `architect.md` | `architect.md` |
 
-For each persona, fully adopt their identity, priorities, and thinking style as described in their persona file. Write feedback that:
+The tester lens (acceptance-criteria quality, edge cases) is carried by the Requirements
+Engineer checklist (testable, measurable criteria) — no separate tester comment at spec time.
 
-- Is **constructive and forward-looking** — no blockers, no verdicts, no approval stamps
+## Step 3 — Run each checklist against the spec
-- Asks clarifying questions the persona would genuinely want answered before or during implementation
-- Points out risks, edge cases, or gaps the persona sees from their domain
-- Offers concrete suggestions or alternative approaches where relevant
-- References the issue text specifically — don't write generic advice
-- Stays focused on what the persona would actually care about (e.g. Felix asks about test strategy and naming; the architect asks about layer boundaries and coupling; the security expert asks about auth, input validation, and data exposure; the tester asks about acceptance criteria and edge cases; the UI expert asks about interaction patterns and accessibility; DevOps asks about deployment, config, and observability)
 
-Format each comment in Markdown with a persona header, e.g.:
+For each persona, walk **every item** in its `.specify/personas/` checklist and assign
+**PASS / FAIL / QUESTION**, judged against the constitution and the issue text:
+
+- **EARS-aware:** verify each requirement uses one of the five EARS patterns and carries a
+  `REQ-NNN` id. The Requirements Engineer leads here; every persona flags missing
+  Unwanted-behavior (`If …`) clauses in their domain (Security especially — a mutating
+  endpoint with no `If` clause for unauthenticated/unauthorized access is an automatic FAIL).
+- **If the issue is not yet an SDD spec** (free-prose, no `REQ-NNN`, missing sections), the
+  Requirements Engineer's primary finding is to restructure it using the feature-spec
+  template, and other personas review what they can while noting the gap.
+- Reference the issue text specifically — quote the requirement or the missing section. No
+  generic advice.
+
+## Step 4 — Write and post each comment
+
+Each persona posts a **separate** comment via the Gitea MCP `issue_write` tool, in the format
+its checklist's "Output format" section defines — a header, the checklist table, and a verdict:
 
 ```
-## 👨‍💻 Felix Brandt — Senior Fullstack Developer
+### 🔐 Security — Spec Review
 
-### Questions & Observations
+| # | Item | Status | Note |
-...
+|---|------|--------|------|
+| 1 | All mutating endpoints have authn + authz `If` clauses | FAIL | REQ-004 POST has no 401 clause (CWE-...) |
+| 2 | ... | PASS | |
 
-### Suggestions
+**Verdict: CHANGES REQUESTED** — blocking FAIL: #1. Resolve before implementation.
-...
 ```
 
-Keep each comment focused and scannable. Use bullet points. Avoid walls of text.
+Post all six comments. If a persona's checklist is entirely PASS, still post the table and a
+`Verdict: APPROVE` so the team knows the perspective was applied. Keep comments scannable.
 
-## Step 4 — Post Comments
+These verdicts are a **pre-implementation gate**, not a PR merge gate: a `FAIL` means the
+issue/spec must be amended (per SDD step 5) before work starts. Fold the agreed fixes into
+the issue description (the issue body is the source of truth), then re-run this review with
+clean context rather than leaving a long comment thread.
 
-Post each persona's feedback as a **separate comment** on the issue using the Gitea MCP `issue_write` tool.
+## Step 5 — Report back
-
-Post all six comments. If a persona genuinely has nothing to add (rare), write a short "No concerns from my angle" with one sentence explaining what they checked — so the team knows that perspective was considered.
-
-## Step 5 — Report Back
 
 After all comments are posted, tell the user:
-- Which personas posted feedback
+- Each persona's verdict (APPROVE / CHANGES REQUESTED)
-- A brief summary of the most important cross-cutting themes (questions or risks that multiple personas flagged)
+- The consolidated list of blocking FAILs (these must be resolved before implementation)
+- Cross-cutting themes multiple personas flagged
+- Whether the issue is a well-formed SDD spec yet, or needs restructuring first
+- A reminder to mirror the agreed `REQ-NNN` rows into [`.specify/rtm.md`](../../../.specify/rtm.md)

.claude/skills/review-pr/SKILL.md

@@ -1,74 +1,95 @@
 ---
 name: review-pr
-description: Multi-persona PR review. Each persona from .claude/personas/ reviews the PR and posts their findings as a separate Gitea comment.
+description: Multi-persona SDD code review of a Gitea PR. Each persona pairs its .claude/personas/ identity with its .specify/personas/ checklist, verifies the diff against the constitution and the feature spec's REQ-NNN (every requirement implemented and tested), and posts findings as a separate Gitea comment.
 ---
 
-# Multi-Persona PR Review
+# Multi-Persona PR Review (SDD)
 
-You will perform a thorough multi-persona code review of the given PR URL and post each persona's findings as a **separate comment** on the PR.
+You will perform a thorough multi-persona code review of the given PR and post each persona's
+findings as a **separate comment**. Under SDD, the review verifies the diff against two
+contracts: the project [constitution](../../../.specify/constitution.md) and the feature's
+spec (the linked **Gitea issue body** — every `REQ-NNN` must be implemented **and** covered by a test).
 
 ## Argument
 
 The user provides a Gitea PR URL, e.g.:
 `http://heim-nas:3005/marcel/familienarchiv/pulls/160`
 
-Parse it to extract:
+Parse it to extract `owner`, `repo`, and `pull_number`.
-- `owner` — e.g. `marcel`
-- `repo` — e.g. `familienarchiv`
-- `pull_number` — e.g. `160`
 
-## Step 1 — Gather PR Context
+## Step 0 — Load the SDD ground truth
+
+Read before reviewing:
+- [`.specify/constitution.md`](../../../.specify/constitution.md) — rules the code must obey (esp. §4 Do-Not-Touch)
+- [`.specify/AGENTS.md`](../../../.specify/AGENTS.md) — constraints
+- The feature's spec — the **Gitea issue** the PR closes (`Closes #n`). Read its body for the
+  `REQ-NNN` requirements, acceptance criteria, inline API stub, and any STRIDE/threat notes.
+- [`.specify/rtm.md`](../../../.specify/rtm.md) — the requirement→test→status matrix
+
+## Step 1 — Gather PR context
 
 Use the Gitea MCP tools to collect:
-1. PR metadata (title, description, base branch, head branch) via `pull_request_read`
+1. PR metadata (title, description, base/head branch) via `pull_request_read`
-2. The list of changed files via `get_dir_contents` or the PR files endpoint
+2. The list of changed files
-3. The full diff / file contents of every changed file — read each file at the head commit using `get_file_contents`
+3. The full content of every changed file at the head commit via `get_file_contents`
 
-Read ALL changed files completely before starting any review. Do not skip files.
+Read ALL changed files completely before starting. Do not skip files.
 
-## Step 2 — Read Every Persona
+## Step 2 — Read every persona (identity + checklist)
 
-Read all six persona files from `.claude/personas/`:
+Adopt each persona's voice from `.claude/personas/`; apply its review lens. For the SDD
-- `developer.md` → Felix Brandt
+personas, also re-read the matching `.specify/personas/` checklist — at PR time the same
-- `architect.md` → architect persona
+checklist items are verified against the **code** rather than the spec.
-- `tester.md` → tester persona
-- `security_expert.md` → security persona
-- `ui_expert.md` → UI/UX persona
-- `devops.md` → DevOps persona
 
-## Step 3 — Write Each Review
+| Persona | Identity (`.claude/personas/`) | Checklist (`.specify/personas/`) | PR-time focus |
+|---|---|---|---|
+| Requirements Engineer | `req_engineer.md` | `requirements-engineer.md` | Traceability: every `REQ-NNN` implemented; RTM updated |
+| Developer (Felix Brandt) | `developer.md` | `developer.md` | Clean code, layering, generate:api run, ErrorCode four-site |
+| Tester | `tester.md` | — (uses identity) | Test quality: each REQ has a real failing-first test; edge cases; levels right |
+| Security (Nora "NullX") | `security_expert.md` | `security.md` | authn/authz, IDOR, mass-assignment, `{@html}`, secrets/PII |
+| DevOps | `devops.md` | `devops.md` | migration rollback, env vars, CI guards intact, artifact pin |
+| UI/UX | `ui_expert.md` | `ui-ux.md` | states, i18n, a11y, design tokens |
+| Architect | `architect.md` | `architect.md` | boundaries, ADR present for irreversible choices, no superseded-ADR violation |
 
-For each persona, fully adopt their identity, priorities, and review lens as described in their persona file. Write a review that:
+## Step 3 — Write each review
+
+For each persona, write a review that:
 
 - Opens with a one-line verdict: **✅ Approved**, **⚠️ Approved with concerns**, or **🚫 Changes requested**
-- Lists concrete findings with file paths and line references where relevant
+- Lists concrete findings with file paths and line references; cite the constitution rule
-- Distinguishes blockers (must fix) from suggestions (nice to have)
+  (e.g. "violates §2.4 — `updatedBy` bound from request body") or the `REQ-NNN` at issue
-- Uses the persona's voice and priorities (e.g. Felix cares about TDD and clean code; the security expert checks for injection, auth, and data exposure; the architect checks layer boundaries and coupling)
+- Distinguishes **blockers** (must fix) from **suggestions** (nice to have)
-- Stays focused — only comment on what the persona would actually care about
+- **Requirements Engineer specifically** produces a traceability table — for each `REQ-NNN`:
-
+  is it implemented? is there a test? is `rtm.md` updated to `Done`? Any unimplemented or
-Format each comment in Markdown with a persona header, e.g.:
+  untested REQ is a blocker. Any code behavior with no backing requirement is flagged
+  (scope creep — should it be a new REQ, or removed?).
+- A constitution **Do-Not-Touch** violation (edited generated file, edited shipped migration,
+  edited an Accepted ADR, bumped the artifact action past v3, weakened a CI guard) is always
+  a blocker.
 
 ```
-## 👨‍💻 Felix Brandt — Senior Fullstack Developer
+### 🔐 Security — PR Review
 
 **Verdict: ⚠️ Approved with concerns**
 
 ### Blockers
-...
+- `UserAvatarController.java:42` — REQ-009's 403 path has no test (constitution §2.8)
 
 ### Suggestions
-...
+- ...
 ```
 
-## Step 4 — Post Comments
+## Step 4 — Post comments
 
-Post each persona's review as a **separate comment** on the PR using the Gitea MCP `issue_write` tool (issues and PRs share the comment API in Gitea).
+Post each persona's review as a **separate comment** via the Gitea MCP `issue_write` tool
+(issues and PRs share the comment API). Post all personas; if one has nothing to flag, post a
+brief "LGTM" naming what they checked.
 
-Post all six comments. Do not skip any persona even if their domain has nothing to flag — in that case write a brief "LGTM" with a short explanation of what they checked.
+## Step 5 — Report back
 
-## Step 5 — Report Back
+Summarize to the user:
-
+- Each persona's verdict and the overall verdict (worst-case wins: any "Changes requested" → overall "Changes requested")
-After all comments are posted, summarize to the user:
+- The full list of blockers, grouped by persona
-- Which personas posted comments
+- **Traceability status:** which `REQ-NNN` are implemented+tested vs. missing, and whether
-- The overall verdict across all personas (worst-case wins: if any said "Changes requested", the overall is "Changes requested")
+  `rtm.md` is in sync
-- A bullet list of the top blockers found (if any)
+- Any constitution Do-Not-Touch violations (called out explicitly)

.gitea/ISSUE_TEMPLATE/bug.md

@@ -0,0 +1,40 @@
+---
+name: "Bug"
+about: "Something is broken. Describe user-facing impact, not the technical cause."
+title: "<What breaks> when <trigger>"
+labels:
+  - bug
+assignees: []
+---
+
+<!--
+  Title format (COLLABORATING.md): "<What breaks> when <trigger>", e.g.
+  "Upload fails silently when file exceeds 50MB". Keep it focused — a bug is small and direct.
+  A failing test is written first, then the fix (red/green TDD).
+-->
+
+## What happens
+
+<The observed broken behavior, from the user's perspective.>
+
+## Expected
+
+<What should happen instead.>
+
+## Steps to reproduce
+
+1.
+2.
+3.
+
+## Originating requirement (if known)
+
+<REQ-NNN + feature this regresses, from .specify/rtm.md — e.g. "REQ-008 (profile-picture-upload)". Helps target the failing test. Write "unknown" if not traceable.>
+
+## Environment
+
+<Browser / role / data state / deploy (local vs prod) as relevant.>
+
+## Notes
+
+<Logs, GlitchTip link, screenshots. Redact PII.>

.gitea/ISSUE_TEMPLATE/feature.md

@@ -0,0 +1,81 @@
+---
+name: "Feature (SDD spec)"
+about: "Spec-driven feature request. Fill in EARS requirements before implementation starts."
+title: "As a <role> I want <capability> so <reason>"
+labels:
+  - spec-required
+  - needs-review
+assignees: []
+---
+
+<!--
+  This issue body IS the spec (issue-only — there is no committed spec.md). Every requirement
+  uses an EARS pattern + a REQ-NNN id. Reference: .specify/templates/feature-spec.md and the
+  worked example .specify/features/_example/. Delete the placeholder hints as you fill each section.
+-->
+
+## Context & Why
+
+<Who needs this and why now (2–4 sentences). Link the constitution principle(s) this depends on: .specify/constitution.md>
+
+## User Journey
+
+<Plain-prose steps the user takes to get value, from the user's perspective. Anything not here is out of scope.>
+
+## Requirements
+
+<!-- One per line, each REQ-NNN + one EARS pattern. A mutating feature needs at least one Event-driven and one Unwanted-behavior requirement. -->
+
+- **REQ-001** (Ubiquitous) — The `<component>` shall `<always-true behavior>`.
+- **REQ-002** (Event-driven) — When `<trigger>`, the `<component>` shall `<response>`.
+- **REQ-003** (State-driven) — While `<state>`, the `<component>` shall `<behavior>`.
+- **REQ-004** (Optional-feature) — Where `<caller has Permission.X / flag set>`, the `<component>` shall `<behavior>`.
+- **REQ-005** (Unwanted-behavior) — If `<undesired condition>`, then the `<component>` shall `<safe response / ErrorCode>`.
+
+## Acceptance Criteria
+
+<!-- One measurable criterion per REQ-NNN: numbers, limits, status codes — not adjectives. -->
+
+- **REQ-001** — <measurable>.
+- **REQ-002** — <measurable>.
+
+## Out of Scope
+
+- <The nearest tempting scope creep, named and excluded.>
+
+## API / Contract Stub
+
+<Inline OpenAPI stub (use .specify/templates/api-contract-stub.md as a writing aid). Name new paths/methods/status codes and the @RequirePermission on each mutating endpoint.>
+
+## Data Model Changes
+
+<Schema delta + next free Flyway V<n> (verify on disk) + rollback note. "none" if not applicable.>
+
+## Security Considerations
+
+<STRIDE categories touched (+ ASTRIDE if an AI agent/tool is involved). Link a threat-model.md if the attack surface is non-trivial.>
+
+## Open Questions
+
+<!-- Each item BLOCKS implementation until resolved. -->
+
+- [ ] <question> — owner: <name>
+
+## Traceability
+
+| REQ-ID | Task ID(s) | Test ID(s) | Status |
+|---|---|---|---|
+| REQ-001 |  |  | Planned |
+
+<!-- Mirror these rows into .specify/rtm.md. -->
+
+## Persona Review Results
+
+| Persona | Status | Key Findings | Resolved |
+|---|---|---|---|
+| Requirements Engineer | PENDING |  |  |
+| Developer | PENDING |  |  |
+| Security | PENDING |  |  |
+| DevOps | PENDING |  |  |
+| UI/UX | PENDING |  |  |
+| Architect | PENDING |  |  |

.gitea/workflows/sdd-gate.yml

@@ -0,0 +1,169 @@
+name: SDD Gate
+
+# Spec-Driven Development quality gate. Runs on PRs.
+#
+# This project is ISSUE-ONLY: a feature's spec lives in its Gitea issue body, not a committed
+# spec.md (see ADR-042). So CI cannot lint the spec text itself — instead it validates the SDD
+# artifacts that DO live in git: the RTM, any committed OpenAPI contract, and the constitution.
+#
+# The first two jobs are NON-BLOCKING for now (continue-on-error) so the team can adopt the
+# workflow without CI immediately failing.
+#
+# TODO: flip rtm-check and contract-validate to BLOCKING (remove `continue-on-error: true`)
+#       once SDD adoption has settled — target: after the first 5 features have shipped through
+#       the workflow. Tracked in ADR-042.
+
+on:
+  pull_request:
+
+jobs:
+  # ─── RTM check ────────────────────────────────────────────────────────────────
+  # The Requirements Traceability Matrix is the one per-feature SDD artifact in git. Every
+  # data row must point at a Gitea issue (`#n`) and name at least one test. Warn otherwise.
+  # Pure awk — no external tooling. Columns: | REQ-ID | Summary | Issue | Feature | Impl | Test | Status |
+  rtm-check:
+    name: RTM Check
+    runs-on: ubuntu-latest
+    continue-on-error: true   # TODO: remove to make blocking (see header)
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Validate .specify/rtm.md rows
+        shell: bash
+        run: |
+          set -uo pipefail
+          rtm=".specify/rtm.md"
+          test -f "$rtm" || { echo "::error::$rtm is missing"; exit 1; }
+
+          # Self-test: a good row passes, a row with an empty Issue or Test is flagged.
+          check_row() { awk -F'|' '{
+            issue=$4; test_col=$7;
+            gsub(/^[ \t]+|[ \t]+$/,"",issue); gsub(/^[ \t]+|[ \t]+$/,"",test_col);
+            if (issue !~ /#/ || test_col=="") exit 1; else exit 0 }'; }
+          echo '| REQ-001 | x | #42 | f | impl | SomeTest#works | Done |'  | check_row \
+            || { echo "FAIL: rtm-check self-test rejected a valid row"; exit 1; }
+          echo '| REQ-002 | x |     | f | impl |               | Planned |' | check_row \
+            && { echo "FAIL: rtm-check self-test accepted an empty row"; exit 1; }
+
+          bad=0
+          while IFS= read -r line; do
+            echo "$line" | check_row || {
+              req=$(echo "$line" | awk -F'|' '{gsub(/^[ \t]+|[ \t]+$/,"",$2); print $2}')
+              echo "::warning file=$rtm::row $req is missing an Issue (#n) or a Test"
+              bad=$((bad+1))
+            }
+          done < <(grep -E '^\| REQ-[0-9]{3} ' "$rtm")
+          echo "$bad RTM row(s) incomplete (warning only)."
+
+  # ─── Contract validation ──────────────────────────────────────────────────────
+  # Validate any committed OpenAPI contract with Spectral (OpenAPI 3.1). REST stack — no
+  # GraphQL. Contracts are optional and ride a feature branch when present; the _example one
+  # is always linted. Skips cleanly when none changed.
+  contract-validate:
+    name: Contract Validate
+    runs-on: ubuntu-latest
+    continue-on-error: true   # TODO: remove to make blocking (see header)
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '24'
+
+      # Cache the npm/npx download so Spectral isn't re-fetched every run. The key is pinned to
+      # the exact Spectral version below, so a version bump busts the cache deterministically.
+      - name: Cache Spectral (npm cache)
+        uses: actions/cache@v4
+        with:
+          path: ~/.npm
+          key: spectral-cli-6.16.0
+          restore-keys: spectral-cli-
+
+      - name: Lint changed OpenAPI contracts
+        shell: bash
+        env:
+          SPECTRAL: "@stoplight/spectral-cli@6.16.0"   # pinned — keep in sync with the cache key above
+        run: |
+          set -uo pipefail
+          base="origin/${{ github.event.pull_request.base.ref }}"
+          git fetch --no-tags --depth=1 origin "${{ github.event.pull_request.base.ref }}" || true
+          # Any *.yaml under .specify/ or any file named like a contract.
+          changed="$(git diff --name-only "$base"...HEAD -- '.specify/**/*.yaml' '**/api-contract.yaml' '**/*.openapi.yaml' || true)"
+          if [ -z "$changed" ]; then
+            echo "No OpenAPI contract changed — nothing to validate."
+            exit 0
+          fi
+          rc=0
+          for f in $changed; do
+            [ -f "$f" ] || continue
+            echo "── spectral lint $f"
+            npx --yes "$SPECTRAL" lint "$f" || rc=1
+          done
+          exit $rc
+
+  # ─── Constitution change impact ───────────────────────────────────────────────
+  # When .specify/constitution.md is modified, list every file that references it (and so
+  # may need a Sync Impact update) and post it as a PR comment. Best-effort: if no token is
+  # available the list is only echoed to the log. This job is informational, never blocking.
+  constitution-diff:
+    name: Constitution Impact
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: List files referencing the constitution
+        id: impact
+        shell: bash
+        run: |
+          set -uo pipefail
+          base="origin/${{ github.event.pull_request.base.ref }}"
+          git fetch --no-tags --depth=1 origin "${{ github.event.pull_request.base.ref }}" || true
+          if ! git diff --name-only "$base"...HEAD -- '.specify/constitution.md' | grep -q .; then
+            echo "constitution.md not modified — skipping."
+            echo "changed=false" >> "$GITHUB_OUTPUT"
+            exit 0
+          fi
+          echo "changed=true" >> "$GITHUB_OUTPUT"
+          echo "Files referencing constitution.md (review for Sync Impact):"
+          grep -rIl --exclude-dir=.git --exclude-dir=node_modules --exclude-dir=target \
+            -e 'constitution.md' -e 'constitution §' . \
+            | grep -v '^\./.specify/constitution.md$' | sort > /tmp/refs.txt || true
+          cat /tmp/refs.txt
+          {
+            echo "body<<EOF"
+            echo "### ⚠️ Constitution changed — Sync Impact review"
+            echo ""
+            echo "\`.specify/constitution.md\` was modified in this PR. Per its §6 Sync Impact rule, re-read and reconcile every file below, and confirm the semantic version bump:"
+            echo ""
+            while IFS= read -r line; do echo "- \`${line#./}\`"; done < /tmp/refs.txt
+            echo "EOF"
+          } >> "$GITHUB_OUTPUT"
+
+      - name: Post PR comment (best-effort)
+        if: steps.impact.outputs.changed == 'true'
+        shell: bash
+        env:
+          TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          SERVER: ${{ github.server_url }}
+          REPO: ${{ github.repository }}
+          PR: ${{ github.event.pull_request.number }}
+          BODY: ${{ steps.impact.outputs.body }}
+        run: |
+          set -uo pipefail
+          if [ -z "${TOKEN:-}" ]; then
+            echo "No token available — printing impact list to log only:"
+            echo "$BODY"
+            exit 0
+          fi
+          payload="$(jq -n --arg b "$BODY" '{body:$b}')"
+          curl -sS -X POST \
+            -H "Authorization: token ${TOKEN}" \
+            -H "Content-Type: application/json" \
+            "${SERVER}/api/v1/repos/${REPO}/issues/${PR}/comments" \
+            -d "$payload" >/dev/null \
+            && echo "Posted Sync Impact comment to PR #${PR}." \
+            || { echo "Comment POST failed (non-fatal); impact list:"; echo "$BODY"; }

.specify/AGENTS.md

@@ -0,0 +1,77 @@
+# AGENTS.md
+
+Machine-readable rules for AI coding agents (Claude Code, Copilot, Cursor, …) working in
+this repository. Read this on every invocation. These are **executable constraints**, not
+aspirations. The full rationale lives in [constitution.md](./constitution.md) and the docs
+it links — this file does not duplicate it, it points to it.
+
+If anything here conflicts with the user's explicit instruction, the user wins. Otherwise,
+constitution > this file > convenience.
+
+---
+
+## Stack & Versions
+
+| Layer | Tech | Version |
+|---|---|---|
+| Backend | Spring Boot (Java, Maven, Jetty, JPA/Hibernate, Flyway, Spring Security, Session JDBC) | Boot 4.0.6 / Java 21 |
+| API docs | springdoc-openapi (webmvc-ui), served at `/v3/api-docs` (dev profile only) | — |
+| Frontend | SvelteKit / Svelte | 2.60 / 5.43 |
+| Frontend lang/style | TypeScript / Tailwind CSS / Paraglide i18n (de/en/es) | TS 5.9 / TW 4.1 |
+| API client | `openapi-fetch` + `openapi-typescript` (types generated from the live spec) | — |
+| DB | PostgreSQL | 16 |
+| Object storage | MinIO (S3-compatible) | — |
+| Sidecars | `ocr-service`, `nlp-service` (Python / FastAPI) | Python 3.11 |
+| Tests | JUnit + Mockito + `@WebMvcTest` + Testcontainers (backend); Vitest + `vitest-browser-svelte` + Playwright (frontend); Pytest (services) | — |
+| Lint/format | ESLint 9 (+ `eslint-plugin-boundaries`) + Prettier; Semgrep (backend) | — |
+| CI | Gitea Actions (`.gitea/workflows/`) | — |
+
+App port `8080`; management port `8081`. Backend app id: `org.raddatz.familienarchiv` / `0.0.1-SNAPSHOT`.
+
+## Architectural Constraints
+
+- Controllers call services only — never a repository. (constitution §1.2)
+- A service uses only its own domain's repository; reach other domains via their service. (constitution §1.3)
+- A new backend domain goes in its own package AND is added to `ArchitectureTest`'s allow-lists in the same change. (constitution §1.7)
+- Frontend cross-domain imports are allowed only where `frontend/eslint.config.js` permits; otherwise move shared code to `$lib/shared/`. (constitution §1.4)
+- Never serialize a lazy-collection entity across the controller boundary — assemble a view in-transaction. (constitution §1.6 / ADR-036)
+- `Person` ≠ `AppUser`; do not add account guards to Person-domain operations. (constitution §1.5)
+- Every `POST/PUT/PATCH/DELETE` endpoint has `@RequirePermission(Permission.X)`. Use the enum, never `@PreAuthorize`. (constitution §2.1–2.2)
+- Throw only `DomainException.notFound/forbidden/conflict/internal()` from services, each with an `ErrorCode`. (CONTRIBUTING §Error handling)
+- Set `createdBy`/`updatedBy` from the session principal in the service — never bind them from a request body. (constitution §2.4)
+- Add an `@Schema(requiredMode = REQUIRED)` to every always-populated field. (constitution §3.5)
+- Never introduce a new runtime dependency without an ADR in `Accepted` status. (constitution §5.1)
+- Render untrusted text with `{...}`; never `{@html}` on user/import data. (constitution §2.5)
+- Build dates from ISO strings with a `T12:00:00` suffix. (constitution §3.7)
+
+## Workflow Rules
+
+- Always write a failing test before implementation code; confirm it fails, then make it pass, then refactor. (constitution §3.1)
+- Run only the specific test file/class locally — never the full suite (it crashes the machine); leave the full sweep to CI.
+- Run `npm run generate:api` (in `frontend/`) after ANY backend model or endpoint change — most common cause of TS errors.
+- Run `npm run lint` before every commit; a fresh frontend worktree needs `npm install` first or the pre-commit hook fails.
+- When adding a new `ErrorCode`, update all four sites at once (constitution §3.6).
+- One logical change per commit; reference the Gitea issue (`Closes #n` / `Refs #n`) on the last line.
+- Create a git worktree for new issue work — never `git checkout -b` in the main repo while another branch has in-flight work. Avoid `+` in worktree/branch names (breaks vitest browser mode).
+- Pull `main` as a separate explicit step before creating a branch.
+- Track work as Gitea issues (`http://192.168.178.71:3005`, repo `marcel/familienarchiv`), not todo files.
+- Verify ADR and Flyway migration numbers against disk before using one — parallel worktrees make issue-body numbers go stale.
+
+## Do Not Touch
+
+- Generated: `frontend/src/lib/generated/api.ts`, `frontend/src/lib/paraglide/`, `frontend/.svelte-kit/`, `frontend/build/`, `backend/target/`.
+- Shipped Flyway migrations — add a new forward-only migration instead.
+- An `Accepted` ADR — supersede it with a new one.
+- `actions/(upload|download)-artifact` version — stays at `@v3` (ADR-014).
+- CI guard steps — do not remove/weaken without an ADR.
+- `main` — never commit directly; branch + PR only.
+- Worktree copies (`familienarchiv-*`, `.worktrees/`) and `data/` — never commit.
+
+## Spec-Driven Development
+
+A feature's spec is its **Gitea issue body** — there is no committed `spec.md`. The issue's
+EARS requirements (`REQ-NNN`) and acceptance criteria are the contract; each maps to a test,
+traced in [`.specify/rtm.md`](./rtm.md) (`REQ-ID → issue # → test`). Read the issue before
+implementing. The committed [`.specify/features/_example/`](./features/_example/) is a
+template/reference showing the full artifact set, not a live feature. Full workflow:
+[SPEC_DRIVEN_DEVELOPMENT.md](../SPEC_DRIVEN_DEVELOPMENT.md).

.specify/adrs/README.md

@@ -0,0 +1,25 @@
+# ADR archive — see `docs/adr/`
+
+This project already keeps a mature, permanent ADR archive at
+[`../../docs/adr/`](../../docs/adr/) (40+ records, format `NNN-kebab-title.md`). SDD does
+**not** introduce a second archive — that would split the project's decision history in two.
+
+## Where ADRs live
+
+- **Project-wide decisions** → [`docs/adr/NNN-kebab-title.md`](../../docs/adr/). Use the
+  next free `NNN` (verify against the directory on disk — parallel worktrees make
+  issue-body numbers stale). Template: [`../templates/adr.md`](../templates/adr.md).
+- **The decision to adopt SDD itself** →
+  [`docs/adr/042-sdd-adoption.md`](../../docs/adr/042-sdd-adoption.md) (this is the
+  "ADR-000" the SDD scaffold calls for, numbered to fit the existing sequence).
+- **Feature-local decisions** that are only meaningful within one in-flight feature →
+  beside that feature's spec, e.g.
+  [`../features/_example/adr-001-avatars-reuse-archive-bucket.md`](../features/_example/adr-001-avatars-reuse-archive-bucket.md).
+  Promote one to `docs/adr/` if its reach turns out to be project-wide.
+
+## Rules (unchanged from the existing convention)
+
+- An ADR is **immutable once `Accepted`** — supersede it with a new, higher-numbered ADR;
+  set the old one's status to `Superseded by ADR-MMM`.
+- Header style matches the existing archive: `# ADR-NNN — Title`, then
+  `**Status:** / **Date:** / **Issue:**`.

.specify/constitution.md

@@ -0,0 +1,80 @@
+# Familienarchiv Constitution
+
+**Version:** v1.0.0
+**Status:** Ratified
+**Date:** 2026-06-13
+**Adoption ADR:** [docs/adr/042-sdd-adoption.md](../docs/adr/042-sdd-adoption.md)
+
+> The non-negotiable rules of this project. Every spec, every PR, and every AI agent is
+> bound by this document. Rules here are deliberately few and absolute — guidance and
+> rationale live in [CLAUDE.md](../CLAUDE.md), [COLLABORATING.md](../COLLABORATING.md),
+> [CODESTYLE.md](../CODESTYLE.md), [CONTRIBUTING.md](../CONTRIBUTING.md), and the ADR
+> archive ([docs/adr/](../docs/adr/)). When this file conflicts with any of those, **this
+> file wins** — open an ADR to change it.
+>
+> Versioning is semantic: **MAJOR** = a rule removed or weakened (existing code may now
+> violate the constitution), **MINOR** = a rule added or tightened, **PATCH** = wording
+> only. Any change requires the Sync Impact review in the last section.
+
+---
+
+## 1. Architecture Principles
+
+1. The backend is organised package-by-domain under `org.raddatz.familienarchiv`; a new domain lives in its own package, never spread across layer packages.
+2. Controllers never call repositories directly — a controller calls only services.
+3. A service accesses only its own domain's repository; cross-domain data is fetched through the other domain's service, never its repository.
+4. The frontend mirrors the backend domain split under `frontend/src/lib/<domain>/`, and cross-domain imports are allowed only where `frontend/eslint.config.js` (`boundaries/dependencies`) permits them.
+5. A `Person` (historical subject) and an `AppUser` (login account) are distinct domains and never share an identity or an account guard.
+6. Lazy-collection-bearing entities are never serialized across the controller boundary; the owning service assembles an explicit view inside the transaction (see [ADR-036](../docs/adr/036-geschichte-responses-are-views-not-entities.md)).
+7. A new backend domain package is added to `ArchitectureTest`'s package allow-lists in the same change that introduces it.
+8. Synchronous cross-domain side effects use in-transaction domain events, not direct service-to-service write calls (see [ADR-006](../docs/adr/006-synchronous-domain-events-in-transaction.md)).
+
+## 2. Security Defaults
+
+1. Every `POST`, `PUT`, `PATCH`, and `DELETE` endpoint carries `@RequirePermission(Permission.X)` — there is no unguarded mutating endpoint.
+2. Authorization uses the typed `Permission` enum and `@RequirePermission`, never magic-string `@PreAuthorize`.
+3. All user input is validated at the system boundary (controller / form action), and validation failures return a typed `ErrorCode`, never a raw exception.
+4. Audit fields (`createdBy`/`updatedBy`) are set from the session principal inside the service and are never bound from a request body.
+5. Untrusted text is rendered through Svelte's default `{...}` escaping; `{@html}` is never used on user- or import-derived strings.
+6. Secrets are read only from environment variables (see `.env.example`); no secret, token, password, or DSN is ever committed to the repository or written to a log.
+7. Logs never contain PII beyond a stable user/entity UUID — no names, email addresses, document contents, or transcription text.
+8. Every state-mutating endpoint is covered by an Unwanted-behavior requirement (EARS `If`) describing the unauthenticated/unauthorized response.
+9. A dependency security audit runs on every CI run (`npm audit --audit-level=high` frontend, Semgrep `.semgrep/security.yml` backend) and nightly; a `high` finding blocks merge.
+
+## 3. Code Quality Rules
+
+1. All new behavior is driven by a failing test written before the implementation (Red → Green → Refactor); a passing-on-first-run test proves nothing and is rejected.
+2. KISS beats DRY — no premature abstraction; an abstraction is introduced only on the third real caller.
+3. Each commit does exactly one logical thing and references its Gitea issue (`Closes #n` / `Refs #n`) on the last line of the body.
+4. No backwards-compatibility shims are added for code that has no callers.
+5. Every entity/DTO field the backend always populates carries `@Schema(requiredMode = REQUIRED)`, and `npm run generate:api` is run after any backend model or endpoint change.
+6. A new `ErrorCode` is added in all four places at once: `ErrorCode.java`, `frontend/src/lib/shared/errors.ts`, `getErrorMessage()`, and `messages/{de,en,es}.json`.
+7. Dates built from an ISO date string append `T12:00:00` to avoid UTC off-by-one.
+8. `npm run lint` (Prettier + ESLint, including the domain boundary rule) passes before every commit.
+
+## 4. Do-Not-Touch List
+
+1. Do not edit generated artifacts: `frontend/src/lib/generated/api.ts`, `frontend/src/lib/paraglide/`, `frontend/.svelte-kit/`, `frontend/build/`, `backend/target/`.
+2. Do not edit an `Accepted` ADR — supersede it with a new, higher-numbered ADR.
+3. Do not upgrade `actions/upload-artifact` / `download-artifact` past `@v3` (Gitea act_runner lacks the v4 protocol — [ADR-014](../docs/adr/014-upload-artifact-v3-pin.md)).
+4. Do not remove or weaken a CI guard step (banned-pattern greps, self-tested regexes) without an ADR recording why.
+5. Do not commit to `main` directly — all work flows through a branch and a PR.
+6. Do not edit a Flyway migration that has shipped; add a new forward-only migration instead.
+7. Do not commit the worktree copy directories (`familienarchiv-*`, `.worktrees/`) or `data/`.
+
+## 5. Dependency Policy
+
+1. A new runtime dependency (backend `pom.xml` or frontend `dependencies`) requires an ADR in `Accepted` status before it is merged.
+2. A new dependency must be version-pinned in the manifest, and any exact pin (no caret) carries a comment stating why it cannot float (see the `@vitest/browser-playwright` pin).
+3. Renovate manages dependency-update PRs; a major-version bump is treated as a feature requiring its own spec and review, not an auto-merge.
+4. A dependency with an unresolved `high`+ advisory is not merged; it is pinned to a safe version or replaced.
+
+## 6. Sync Impact
+
+When this constitution changes, the author MUST, in the same PR:
+
+1. Bump the **Version** header per the semantic rule above and record the change in [docs/adr/042-sdd-adoption.md](../docs/adr/042-sdd-adoption.md)'s revision log (or a superseding ADR for a MAJOR change).
+2. Re-read and reconcile every file that restates a rule changed here: `CLAUDE.md`, `COLLABORATING.md`, `CODESTYLE.md`, `CONTRIBUTING.md`, `.specify/AGENTS.md`, and the affected `.specify/personas/*.md` checklists.
+3. Update any `.specify/templates/*` section that quotes a changed rule.
+4. Run the `constitution-diff` CI job locally (or read its PR comment) and resolve every file it lists.
+5. Announce the version bump in the PR description so reviewers re-read the constitution before approving.

.specify/features/_example/adr-001-avatars-reuse-archive-bucket.md

@@ -0,0 +1,46 @@
+# ADR-001 (feature-local) — Avatars reuse the archive bucket under an `avatars/` prefix
+
+**Status:** Accepted
+**Date:** 2026-06-13
+**Issue:** #<example> (profile picture upload)
+
+> **Feature-local ADR.** This decision is scoped to the avatar feature and lives with its
+> spec. A decision with project-wide reach is promoted to the permanent archive at
+> `docs/adr/` with the next free number. (For the worked example, it stays local.)
+
+## Context
+
+Avatars are small binary objects keyed per user. The project already runs MinIO with a
+single archive bucket and a `FileService` abstraction used by document uploads. We must
+decide where avatar bytes live without adding operational surface that the self-hosted
+Compose deployment has to learn about.
+
+## Decision
+
+Store each avatar in the **existing archive bucket** under the deterministic key
+`avatars/{userId}`, written and read through the existing `FileService`. No new bucket, no
+new env var, no new Compose service or bucket-bootstrap step.
+
+## Alternatives Considered
+
+| Option | Pros | Cons | Reason rejected |
+|---|---|---|---|
+| Reuse archive bucket, `avatars/` prefix | No infra change; reuses `FileService`; idempotent overwrite | Mixes avatars with documents in one bucket | **Chosen** — least operational cost; prefix keeps them logically separate |
+| Dedicated `avatars` bucket | Clean separation; independent lifecycle/policy | New bucket + bootstrap step + env var + Compose idempotency test | Operational overhead not justified for small, low-value objects |
+| Store bytes in PostgreSQL (`bytea`) | One datastore; transactional with the row | Bloats the DB and backups; streaming images via JPA is awkward | Wrong tool; MinIO already exists for blobs |
+| External CDN / object store | Offloads bandwidth | New third-party dependency + secret + ADR; conflicts with self-hosted goal | Contradicts the self-hosted infrastructure stance |
+
+## Consequences
+
+- No deployment change ships with this feature — only a Flyway column and code.
+- Avatars and documents share a bucket; any future per-object lifecycle policy must filter
+  by the `avatars/` prefix.
+- The deterministic key (`avatars/{userId}`, no random suffix) makes replace an overwrite,
+  so there is no orphan-cleanup obligation (REQ-001).
+- If avatars later need independent retention or a public CDN, this ADR is superseded by a
+  project-wide ADR in `docs/adr/`.
+
+## References
+
+- [`./spec.md`](./spec.md), [`./design.md`](./design.md)
+- [constitution §5 Dependency Policy](../../constitution.md#5-dependency-policy)

.specify/features/_example/api-contract.yaml

@@ -0,0 +1,140 @@
+openapi: 3.1.0
+info:
+  title: Familienarchiv API — Profile picture upload
+  version: 0.0.1-SNAPSHOT
+  description: >
+    Design-time contract for the avatar feature (.specify/features/_example).
+    Source of truth once shipped is the generated /v3/api-docs.
+servers:
+  - url: http://localhost:8080
+    description: Local backend (dev profile)
+  - url: https://archiv.raddatz.cloud
+    description: Production (behind Caddy)
+components:
+  securitySchemes:
+    cookieAuth:
+      type: apiKey
+      in: cookie
+      name: SESSION
+  schemas:
+    ErrorResponse:
+      type: object
+      required: [code, message]
+      properties:
+        code:
+          type: string
+          example: AVATAR_TOO_LARGE
+        message:
+          type: string
+    UserProfileView:
+      type: object
+      required: [id, displayName]
+      properties:
+        id:
+          type: string
+          format: uuid
+        displayName:
+          type: string
+        avatarUrl:
+          type: [string, "null"]
+          description: Authenticated proxy path (/api/users/{id}/avatar) when an avatar exists, else null.
+          example: /api/users/3f1c.../avatar
+security:
+  - cookieAuth: []
+paths:
+  /api/users/me/avatar:
+    post:
+      summary: Upload or replace the current user's avatar
+      tags: [Users]
+      operationId: uploadMyAvatar
+      security:
+        - cookieAuth: []
+      requestBody:
+        required: true
+        content:
+          multipart/form-data:
+            schema:
+              type: object
+              required: [file]
+              properties:
+                file:
+                  type: string
+                  format: binary
+                  description: PNG or JPEG, max 2 MB.
+      responses:
+        '200':
+          description: Avatar stored; updated profile returned.
+          content:
+            application/json:
+              schema: { $ref: '#/components/schemas/UserProfileView' }
+        '400':
+          description: Unsupported type (UNSUPPORTED_FILE_TYPE) or too large (AVATAR_TOO_LARGE).
+          content:
+            application/json:
+              schema: { $ref: '#/components/schemas/ErrorResponse' }
+        '401':
+          description: Unauthenticated (UNAUTHORIZED).
+          content:
+            application/json:
+              schema: { $ref: '#/components/schemas/ErrorResponse' }
+    delete:
+      summary: Remove the current user's avatar
+      tags: [Users]
+      operationId: deleteMyAvatar
+      security:
+        - cookieAuth: []
+      responses:
+        '200':
+          description: Avatar removed; profile returned with avatarUrl null.
+          content:
+            application/json:
+              schema: { $ref: '#/components/schemas/UserProfileView' }
+        '401':
+          description: Unauthenticated (UNAUTHORIZED).
+          content:
+            application/json:
+              schema: { $ref: '#/components/schemas/ErrorResponse' }
+  /api/users/{id}/avatar:
+    get:
+      summary: Stream a user's avatar image (authenticated proxy)
+      tags: [Users]
+      operationId: getUserAvatar
+      security:
+        - cookieAuth: []
+      parameters:
+        - name: id
+          in: path
+          required: true
+          schema: { type: string, format: uuid }
+      responses:
+        '200':
+          description: Image bytes.
+          content:
+            image/png: { schema: { type: string, format: binary } }
+            image/jpeg: { schema: { type: string, format: binary } }
+        '401': { description: Unauthenticated, content: { application/json: { schema: { $ref: '#/components/schemas/ErrorResponse' } } } }
+        '404': { description: User has no avatar, content: { application/json: { schema: { $ref: '#/components/schemas/ErrorResponse' } } } }
+    delete:
+      summary: Remove another user's avatar (admin only)
+      tags: [Users]
+      operationId: deleteUserAvatar
+      description: Requires Permission.ADMIN_USER (enforced by @RequirePermission on the controller).
+      security:
+        - cookieAuth: []
+      parameters:
+        - name: id
+          in: path
+          required: true
+          schema: { type: string, format: uuid }
+      responses:
+        '200':
+          description: Avatar removed.
+          content:
+            application/json:
+              schema: { $ref: '#/components/schemas/UserProfileView' }
+        '401': { description: Unauthenticated, content: { application/json: { schema: { $ref: '#/components/schemas/ErrorResponse' } } } }
+        '403':
+          description: Caller lacks ADMIN_USER (FORBIDDEN).
+          content:
+            application/json:
+              schema: { $ref: '#/components/schemas/ErrorResponse' }

.specify/features/_example/checklist-results.md

@@ -0,0 +1,76 @@
+# Persona Review Results — Profile picture upload
+
+> Captured from the six persona spec reviews (the comments that, in a real feature, are
+> posted on the Gitea issue). This is the worked example of what a completed review round
+> looks like. All personas APPROVE; the two findings raised were folded into the spec
+> before approval.
+
+## Summary
+
+| Persona | Verdict | Blocking FAILs | Notes |
+|---|---|---|---|
+| Requirements Engineer | APPROVE | none | — |
+| Developer | APPROVE | none | — |
+| Security | APPROVE | none (2 resolved) | See F-SEC-1, F-SEC-2 |
+| DevOps | APPROVE | none | — |
+| UI/UX | APPROVE | none (1 resolved) | See F-UX-1 |
+| Architect | APPROVE | none (1 resolved) | See F-ARCH-1 |
+
+---
+
+## ### Security — Spec Review
+
+| # | Item | Status | Note |
+|---|---|---|---|
+| 1 | All mutating endpoints have authn + authz `If` clauses | PASS | REQ-006 (401), REQ-009 (403) |
+| 2 | Each mutating endpoint names least-privilege `Permission` | PASS | `me` = authenticated; `{id}` = ADMIN_USER |
+| 3 | Audit fields server-set, forbidden in body | PASS | `avatarObjectKey` server-set (design.md) |
+| 4 | IDOR surfaces addressed | PASS | `/{id}` gated by ADMIN_USER + ownership |
+| 5 | Untrusted content rendered safely | PASS | image bytes via proxy + `nosniff` |
+| 6 | Upload: type allow-list + size + bytes | PASS | REQ-007 (PNG/JPEG), REQ-008 (2 MB) |
+| 7 | No entity internals leaked | PASS | `UserProfileView`, not `AppUser` |
+| 8 | Conflicts → 409 not raw 500 | N/A | no optimistic-lock surface here |
+| 9 | threat-model.md present & STRIDE-complete | PASS | [threat-model.md](./threat-model.md) |
+| 10 | ASTRIDE if AI tool used | N/A | no AI agent |
+| 11 | Secrets from env only | PASS | none introduced |
+| 12 | Logs PII-free | PASS | user UUID only |
+| 13 | New dependency has ADR + clean audit | N/A | no new dependency |
+
+**F-SEC-1 (resolved):** initial draft exposed a public S3 URL for `avatarUrl` →
+information disclosure. Resolved: authenticated proxy `GET /api/users/{id}/avatar`.
+**F-SEC-2 (resolved):** initial draft bound `avatarObjectKey` from the request body →
+mass-assignment. Resolved: server-set only.
+**Verdict: APPROVE.**
+
+## ### UI/UX — Spec Review
+
+| # | Item | Status | Note |
+|---|---|---|---|
+| 1 | Every interaction state described | PASS | idle/preview/uploading/error/done (T-10) |
+| 2 | Strings via Paraglide i18n | PASS | T-8 |
+| 3 | Reuses design tokens/components | PASS | placeholder uses existing initials pattern |
+| 4 | Responsive per device split | PASS | control usable on phone + laptop |
+| 5 | Errors via `getErrorMessage(code)` | PASS | UNSUPPORTED_FILE_TYPE / AVATAR_TOO_LARGE |
+| 6 | Keyboard + screen-reader | PASS | labelled file input, alt text on image |
+| 7 | Acceptance criteria measurable | PASS | sizes, status codes |
+| 8 | E2E scenario per journey | PASS | T-12 |
+| 9 | Confirmation for destructive action | PASS | remove asks to confirm |
+| 10 | Safe rendering + image dims | PASS | fixed dims avoid layout shift |
+| 11 | Live routes verified | PASS | `/profile`, `/users/[id]` exist |
+| 12 | Token theming respected | PASS | semantic tokens |
+
+**F-UX-1 (resolved):** no loading state in first draft → spinner during upload added (REQ-... covered by state set in T-10).
+**Verdict: APPROVE.**
+
+## ### Architect — Spec Review
+
+Key items PASS. **F-ARCH-1 (resolved):** bucket choice was undocumented → captured in
+[adr-001-avatars-reuse-archive-bucket.md](./adr-001-avatars-reuse-archive-bucket.md). No new
+domain, no boundary crossing, Person/AppUser separation intact. **Verdict: APPROVE.**
+
+## ### Requirements Engineer / Developer / DevOps — Spec Review
+
+All checklist items PASS (see each persona's checklist in `.specify/personas/`). RE: 9 REQ
+ids, all EARS-formed, every limit has an `If`. Developer: reuses `FileService`/`UserService`,
+`AVATAR_TOO_LARGE` four-site update is T-1. DevOps: V78 forward-only + rollback note, no new
+bucket/env var, idempotent overwrite. **All three: APPROVE.**

.specify/features/_example/design.md

@@ -0,0 +1,63 @@
+# Design — Profile picture upload
+
+> Companion to [`./spec.md`](./spec.md). The spec says *what*; this says *how*, and records
+> the alternatives weighed for the non-obvious choices.
+
+## Component overview
+
+```
+ProfileSettings.svelte ──► +page.server.ts (form action)
+        (preview, validate)        │ POST /api/users/me/avatar (multipart)
+                                    ▼
+                         UserAvatarController  ── @RequirePermission(authenticated)
+                                    │            ownership/admin check for /{id}
+                                    ▼
+                            UserService.setAvatar(userId, MultipartFile)
+                                    │ validate type+size → ErrorCode
+                                    ├──► FileService.put("avatars/{userId}", bytes)   (MinIO)
+                                    └──► userRepository.save(user.avatarObjectKey=key)
+                                    ▼
+                            UserProfileView { …, avatarUrl }
+```
+
+Reads: `GET /api/users/{id}/avatar` streams the object through the authenticated API
+(`FileService.get`), so no public S3 URL is ever exposed. `avatarUrl` in the view is simply
+`/api/users/{id}/avatar` when a key exists, else `null`.
+
+## Key decisions
+
+| Decision | Choice | Why |
+|---|---|---|
+| Where avatars live | Existing archive bucket, `avatars/{userId}` prefix | No new bucket/env var/Compose change — see [ADR-001](./adr-001-avatars-reuse-archive-bucket.md). |
+| URL exposure | Authenticated proxy endpoint, not a signed/public URL | Same auth surface as the rest of the API; no key leakage (Information disclosure). |
+| Object key | Deterministic `avatars/{userId}` (no random suffix) | A new upload overwrites the old object — no orphan-cleanup job needed (REQ-001). |
+| `avatarObjectKey` binding | Server-set in `UserService` only | Never bound from request body — prevents pointing a user's avatar at an arbitrary object (Tampering / CWE-639). |
+| Validation site | `UserService`, boundary-only | Type + size checked once, at the service boundary, mapped to `ErrorCode` (constitution §2.3). |
+
+## Layering & conventions
+
+- Controller → `UserService` only; `UserService` owns `userRepository` and calls
+  `FileService` (its public API), never another domain's repository. (constitution §1.2–1.3)
+- New `ErrorCode.AVATAR_TOO_LARGE` requires the four-site update (see `tasks.md` T-1).
+- `UserProfileView.avatarUrl` is `String` (nullable) with `@Schema` describing the proxy
+  path; not marked `requiredMode = REQUIRED` because it is legitimately null (REQ-004).
+- After backend changes: `npm run generate:api` regenerates `avatarUrl` into the TS types.
+
+## Non-functional notes
+
+- Size cap (2 MB, REQ-008) is enforced **before** the object touches MinIO — the multipart
+  is read into a bounded buffer; Spring's `spring.servlet.multipart.max-file-size` is set to
+  a matching ceiling so an oversized body is rejected at the container edge too.
+- No N+1 risk: the profile view derives `avatarUrl` from the already-loaded `avatarObjectKey`
+  column; no extra query, no S3 round-trip on list/read paths.
+- The proxy `GET` streams bytes (no full-buffer) and sets a short `Cache-Control` so an
+  updated avatar propagates quickly.
+
+## Test strategy (maps to tasks.md)
+
+| Level | What | Tooling |
+|---|---|---|
+| Unit | `UserService.setAvatar` validation + storage interactions | JUnit + Mockito (mock `FileService`) |
+| Slice | controller auth, status codes, error codes | `@WebMvcTest` |
+| E2E | upload → preview → confirm → avatar visible; remove → initials | Playwright |
+| Component | initials placeholder when `avatarUrl` is null | `vitest-browser-svelte` (`*.svelte.spec.ts`) |

.specify/features/_example/spec.md

@@ -0,0 +1,118 @@
+# As a user I want to upload a profile picture so other family members recognise me
+
+> **This is the canonical worked example for SDD in this repo.** It is fictional but
+> realistic, chosen because no real avatar feature exists in the codebase. Use it as the
+> reference shape for a real `spec.md`. Every section is filled — no placeholders.
+
+## Context & Why
+
+Readers and transcribers collaborate in threads and on document comments, but every user is
+currently represented by initials only. Letting a user upload a small profile picture makes
+the activity feed, comments, and the public user profile page (`/users/[id]`) more personal
+and easier to scan — directly serving the family-archive product goal of feeling like a
+shared family space, not a database.
+
+Constitution principles this feature depends on:
+- [§2 Security Defaults](../../constitution.md#2-security-defaults) — upload validation, permission gating, no PII in logs.
+- [§1.3 services own their repository](../../constitution.md#1-architecture-principles) — avatar storage goes through `UserService` + `FileService`, not a controller.
+- [§3.6 ErrorCode four-site rule](../../constitution.md#3-code-quality-rules) — introduces `AVATAR_TOO_LARGE`.
+
+Related: builds on the existing `FileService` (MinIO) used by `Document` uploads.
+
+## User Journey
+
+A logged-in user opens their profile settings (`/profile`), clicks "Profilbild ändern",
+selects a PNG or JPEG from their device, sees an instant preview, and confirms. The picture
+replaces their initials everywhere their name appears. They can later remove it and fall
+back to initials. An admin (with `ADMIN_USER`) can remove an inappropriate picture from
+another user's account from the admin user view.
+
+## Requirements
+
+- **REQ-001** (Ubiquitous) — The user service shall store each profile picture as a single object in the existing archive bucket under the key `avatars/{userId}`, overwriting any previous object for that user.
+- **REQ-002** (Event-driven) — When an authenticated user sends `POST /api/users/me/avatar` with a valid image, the user service shall store the image, set the user's `avatarObjectKey`, and return the updated profile view including a non-null `avatarUrl`.
+- **REQ-003** (Event-driven) — When an authenticated user sends `DELETE /api/users/me/avatar`, the user service shall delete the stored object, clear `avatarObjectKey`, and return the profile view with `avatarUrl = null`.
+- **REQ-004** (State-driven) — While a user has no stored avatar, the profile view for that user shall return `avatarUrl = null` and the frontend shall render the initials placeholder.
+- **REQ-005** (Optional-feature) — Where the caller holds `Permission.ADMIN_USER`, the user service shall allow `DELETE /api/users/{id}/avatar` to remove another user's avatar.
+- **REQ-006** (Unwanted-behavior) — If the request to any avatar endpoint is unauthenticated, then the system shall return `401` with `ErrorCode.UNAUTHORIZED` and store or delete nothing.
+- **REQ-007** (Unwanted-behavior) — If the uploaded file's content type is not `image/png` or `image/jpeg`, then the user service shall return `400 ErrorCode.UNSUPPORTED_FILE_TYPE` and store nothing.
+- **REQ-008** (Unwanted-behavior) — If the uploaded file exceeds 2 MB, then the user service shall return `400 ErrorCode.AVATAR_TOO_LARGE` and store nothing.
+- **REQ-009** (Unwanted-behavior) — If a caller without `Permission.ADMIN_USER` targets another user's avatar via `/api/users/{id}/avatar`, then the system shall return `403 ErrorCode.FORBIDDEN` and modify nothing.
+
+## Acceptance Criteria
+
+- **REQ-001** — After a successful upload, exactly one object exists at `avatars/{userId}`; a second upload leaves exactly one object (no orphan), verified by a `FileService` interaction test.
+- **REQ-002** — `POST /api/users/me/avatar` with a 100 KB PNG returns `200` and a body whose `avatarUrl` is a non-null string; the persisted `app_users.avatar_object_key` equals `avatars/{userId}`.
+- **REQ-003** — `DELETE /api/users/me/avatar` returns `200`, the object is gone, and the response `avatarUrl` is `null`.
+- **REQ-004** — `GET` profile view for a user with `avatar_object_key IS NULL` returns `avatarUrl: null`; the rendered component shows a 2-letter initials placeholder (Playwright).
+- **REQ-005** — An `ADMIN_USER` caller deleting another user's avatar returns `200`; the target's `avatar_object_key` becomes `NULL`.
+- **REQ-006** — An unauthenticated `POST`/`DELETE` returns `401`; bucket object count is unchanged.
+- **REQ-007** — A `text/plain` or `application/pdf` upload returns `400 UNSUPPORTED_FILE_TYPE`; bucket object count is unchanged.
+- **REQ-008** — A 2.1 MB PNG returns `400 AVATAR_TOO_LARGE`; bucket object count is unchanged.
+- **REQ-009** — A non-admin caller targeting another user's id returns `403 FORBIDDEN`; the target's `avatar_object_key` is unchanged.
+
+## Out of Scope
+
+- Image cropping, resizing, or transformation — the client sends a final image; the server stores it verbatim within the size limit.
+- Avatars for historical `Person` entities — this feature is for `AppUser` accounts only (Person ≠ AppUser).
+- Gravatar / external avatar providers.
+- Animated formats (GIF/WebP) — PNG and JPEG only in v1.
+
+## API / Contract Stub
+
+See [`./api-contract.yaml`](./api-contract.yaml). Endpoints:
+`POST /api/users/me/avatar` (multipart), `DELETE /api/users/me/avatar`,
+`DELETE /api/users/{id}/avatar` (ADMIN_USER). The profile view gains an optional
+`avatarUrl: string | null`. All mutating endpoints carry `@RequirePermission` — `me`
+endpoints require an authenticated session; the `{id}` delete requires `ADMIN_USER`.
+
+## Data Model Changes
+
+- Add nullable `avatar_object_key VARCHAR(512)` to `app_users`.
+- Flyway `V78__add_app_user_avatar_object_key.sql` (next free number — verify against
+  `backend/src/main/resources/db/migration/` on disk before committing).
+- **Rollback:** forward-only. Reverse manually with `ALTER TABLE app_users DROP COLUMN avatar_object_key;`. The MinIO `avatars/` objects are orphaned but harmless on rollback and can be pruned with `mc rm --recursive`.
+
+## Security Considerations
+
+STRIDE categories touched: **Tampering** (mass-assignment of `avatarObjectKey` if bound from
+body), **Elevation of privilege** (a non-admin modifying another user's avatar — REQ-009),
+**Denial of service** (oversized upload — REQ-008), **Information disclosure** (avatar URL
+must not expose a signed key that bypasses auth). No AI agent involved, so ASTRIDE does not
+apply. Full analysis: [`./threat-model.md`](./threat-model.md).
+
+## Open Questions
+
+> All resolved before implementation.
+
+- [x] Public or signed avatar URL? — **Resolved:** served through an authenticated
+  `GET /api/users/{id}/avatar` proxy (same auth as the rest of the API), not a public S3 URL.
+- [x] New bucket or reuse archive bucket? — **Resolved:** reuse the archive bucket under an
+  `avatars/` prefix; see [`./adr-001-avatars-reuse-archive-bucket.md`](./adr-001-avatars-reuse-archive-bucket.md).
+
+## Traceability
+
+| REQ-ID | Task ID(s) | Test ID(s) | Status |
+|---|---|---|---|
+| REQ-001 | T-3 | `UserServiceAvatarTest#storesUnderUserKey`, `…#replaceLeavesNoOrphan` | Planned |
+| REQ-002 | T-4 | `UserAvatarControllerTest#uploadReturnsAvatarUrl` | Planned |
+| REQ-003 | T-5 | `UserAvatarControllerTest#deleteClearsAvatar` | Planned |
+| REQ-004 | T-7 | `avatar-placeholder.svelte.spec.ts` | Planned |
+| REQ-005 | T-6 | `UserAvatarControllerTest#adminDeletesOthersAvatar` | Planned |
+| REQ-006 | T-2 | `UserAvatarControllerTest#unauthenticatedReturns401` | Planned |
+| REQ-007 | T-2 | `UserAvatarControllerTest#rejectsNonImage` | Planned |
+| REQ-008 | T-2 | `UserAvatarControllerTest#rejectsOversize` | Planned |
+| REQ-009 | T-6 | `UserAvatarControllerTest#nonAdminForbiddenOnOthers` | Planned |
+
+Mirrored in [`.specify/rtm.md`](../../rtm.md).
+
+## Persona Review Results
+
+| Persona | Status | Key Findings | Resolved |
+|---|---|---|---|
+| Requirements Engineer | APPROVE | All 9 REQ ids EARS-formed; every limit has an `If` clause. | — |
+| Developer | APPROVE | Reuses `FileService`/`UserService`; `AVATAR_TOO_LARGE` four-site update listed (T-1). | — |
+| Security | APPROVE | REQ-006/008/009 cover authn/DoS/EoP; `avatarObjectKey` server-set only (see threat model T-1). | Yes |
+| DevOps | APPROVE | V78 forward-only with rollback note; no new bucket/env var. | — |
+| UI/UX | APPROVE | Placeholder + loading/error states specified; strings via i18n (T-8). | — |
+| Architect | APPROVE | Bucket-reuse decision captured in ADR-001; no new domain, no boundary crossing. | Yes |

.specify/features/_example/tasks.md

@@ -0,0 +1,47 @@
+# Tasks — Profile picture upload
+
+> Red/Green TDD order: each implementation task is preceded by the failing test that
+> requires it. Task IDs are referenced from `spec.md` → Traceability and from `.specify/rtm.md`.
+> Check off as work lands; reference the issue in each commit (`Refs #<n>`).
+
+## Backend
+
+- [ ] **T-1** Add `ErrorCode.AVATAR_TOO_LARGE` in all four sites at once: `ErrorCode.java`,
+      `frontend/src/lib/shared/errors.ts`, `getErrorMessage()`, `messages/{de,en,es}.json`.
+      *(No new behavior yet — enables REQ-008's error.)* → covers REQ-008 (error plumbing)
+- [ ] **T-2** `@WebMvcTest` `UserAvatarControllerTest`: write failing slice tests —
+      `unauthenticatedReturns401`, `rejectsNonImage` (400 UNSUPPORTED_FILE_TYPE),
+      `rejectsOversize` (400 AVATAR_TOO_LARGE). Then implement `UserAvatarController` +
+      `@RequirePermission` to green. → REQ-006, REQ-007, REQ-008
+- [ ] **T-3** Unit `UserServiceAvatarTest`: failing tests `storesUnderUserKey`,
+      `replaceLeavesNoOrphan`, validation maps to `DomainException`. Then implement
+      `UserService.setAvatar`/`removeAvatar` (mock `FileService`) to green. → REQ-001, REQ-002, REQ-003
+- [ ] **T-4** Flyway `V78__add_app_user_avatar_object_key.sql` (verify next free number on
+      disk) adding nullable `avatar_object_key VARCHAR(512)`; add the column + `@Schema` to
+      `AppUser` / `UserProfileView` (`avatarUrl` derived). Test: repository round-trip. → REQ-002
+- [ ] **T-5** `deleteMyAvatar` controller test + impl (clears key, deletes object, returns
+      `avatarUrl: null`). → REQ-003
+- [ ] **T-6** Admin path: failing tests `adminDeletesOthersAvatar` (200),
+      `nonAdminForbiddenOnOthers` (403). Implement ownership/`ADMIN_USER` check to green. → REQ-005, REQ-009
+- [ ] **T-7** Authenticated proxy `getUserAvatar` streaming endpoint + `Content-Type` +
+      `X-Content-Type-Options: nosniff`; test 200 bytes / 404 when no avatar. → REQ-004 (view side)
+- [ ] **T-A** Run `npm run generate:api` after T-4/T-7 so `avatarUrl` lands in `api.ts`.
+
+## Frontend
+
+- [ ] **T-8** i18n keys for the new strings in `messages/{de,en,es}.json` (button labels,
+      validation errors mapped via `getErrorMessage`). → REQ-007, REQ-008 (UX)
+- [ ] **T-9** Component test `avatar-placeholder.svelte.spec.ts`: failing test asserting
+      initials render when `avatarUrl` is null; implement the placeholder. → REQ-004
+- [ ] **T-10** `/profile` upload control: file picker, client-side type/size pre-check,
+      instant preview, confirm/remove. States: idle/preview/uploading/error/done. → REQ-002, REQ-003
+- [ ] **T-11** Render avatar where names appear (comments, activity feed, `/users/[id]`),
+      falling back to the placeholder. → REQ-004
+- [ ] **T-12** E2E `avatar.spec.ts`: upload → preview → confirm → avatar visible; remove →
+      initials return. → REQ-002, REQ-003, REQ-004
+
+## Cross-cutting
+
+- [ ] **T-13** Set `spring.servlet.multipart.max-file-size` to a 2 MB-matching ceiling so an
+      oversized body is rejected at the container edge (defense in depth for REQ-008).
+- [ ] **T-14** Update `.specify/rtm.md` Status column to `Done` per REQ as each test goes green.

.specify/features/_example/threat-model.md

@@ -0,0 +1,45 @@
+# Threat Model — Profile picture upload
+
+**Feature spec:** [./spec.md](./spec.md)
+**Date:** 2026-06-13
+**Author:** Security persona (worked example)
+
+## Data Flow Diagram (text)
+
+**Actors**
+- Anonymous visitor (unauthenticated)
+- Authenticated user (uploads their own avatar)
+- Admin (`Permission.ADMIN_USER` — may remove others' avatars)
+
+**Trust boundaries**
+- TB-1: Browser ⇄ Caddy (public internet ⇄ DMZ)
+- TB-2: Caddy ⇄ Backend `:8080` (DMZ ⇄ app)
+- TB-3: Backend ⇄ MinIO + PostgreSQL (app ⇄ data plane)
+
+**Data flows**
+- F-1: Browser → [TB-1,TB-2] → `UserAvatarController` : multipart image
+- F-2: `UserService` → [TB-3] → MinIO : object at `avatars/{userId}`
+- F-3: `UserService` → [TB-3] → PostgreSQL : `app_users.avatar_object_key`
+- F-4: Browser → [TB-1,TB-2,TB-3] → MinIO (via proxy GET) : image bytes
+
+## STRIDE
+
+| Threat Category | Asset / Flow | Threat Description | Mitigation | Likelihood × Impact | Status |
+|---|---|---|---|---|---|
+| **S**poofing | F-1 | Unauthenticated caller uploads/deletes an avatar | Session auth required; `@RequirePermission` (REQ-006) | Low × Med | Mitigated |
+| **T**ampering | F-3 | Caller sets `avatarObjectKey` via request body to point at an arbitrary stored object | `avatarObjectKey` is server-set in `UserService` only, never bound from body (CWE-639) | Med × High | Mitigated |
+| **R**epudiation | F-2/F-3 | No record of who changed an avatar | Standard request logging by user UUID (no PII); admin deletions auditable via existing logs | Low × Low | Accepted |
+| **I**nformation disclosure | F-4 | A public/signed S3 URL would let anyone fetch any avatar without auth | Avatars served only through the authenticated proxy `GET /api/users/{id}/avatar`; no public URL | Med × Med | Mitigated |
+| **I**nformation disclosure | F-1 | Malicious file (polyglot) served back with a sniffed content type → stored XSS | Store with a fixed `image/png`/`image/jpeg` content type; proxy sets `Content-Type` + `X-Content-Type-Options: nosniff`; only PNG/JPEG accepted (REQ-007) | Low × High | Mitigated |
+| **D**enial of service | F-1/F-2 | Oversized or many uploads exhaust storage/memory | 2 MB cap enforced before MinIO write + `multipart.max-file-size` ceiling (REQ-008); deterministic key means one object per user | Med × Med | Mitigated |
+| **E**levation of privilege | F-1 | Non-admin removes/replaces another user's avatar via `/{id}` | Ownership check; `ADMIN_USER` required for `/{id}` (REQ-005/REQ-009, 403) | Low × Med | Mitigated |
+
+## ASTRIDE
+
+Not applicable — this feature invokes no AI agent, model, or tool.
+
+## Residual Risk
+
+- **Repudiation (Accepted):** avatar changes are not written to a dedicated audit table.
+  Accepted because the asset is low-value (a self-chosen picture) and request logs already
+  attribute the action to a user UUID. Revisit if avatars ever become trust signals.

.specify/personas/architect.md

@@ -0,0 +1,40 @@
+# Persona — Architect (spec review)
+
+> Concise spec-review checklist. Full character persona:
+> [`.claude/personas/architect.md`](../../.claude/personas/architect.md). This file gates a
+> `spec.md` and its `design.md`/ADRs for systemic fit and long-term consequence.
+
+## Role summary
+
+I check that a feature fits the system's domain boundaries and decision history, and that
+any irreversible choice it makes is captured in an ADR before code is written. I block specs
+that quietly contradict an Accepted ADR, blur a domain boundary, or bake in a decision with
+no recorded rationale.
+
+## Review checklist (PASS / FAIL / QUESTION per item)
+
+1. Does the feature respect the package-by-domain structure — new code in the right domain, no logic smeared across layer packages?
+2. Does it honor the layering rule and the frontend boundary rule, or does it justify and record any new cross-domain edge?
+3. Does any irreversible or contentious decision (new dependency, new domain, data-model shape, response-as-view vs entity, sync vs async side effect) have an ADR in `Proposed`/`Accepted` status under `docs/adr/`?
+4. Does the spec contradict any existing Accepted ADR — and if a change is intended, does it **supersede** that ADR rather than silently diverge?
+5. Is the ADR number the next free one verified against `docs/adr/` on disk?
+6. Does the design reuse an established pattern (in-transaction views per ADR-036, domain events per ADR-006, DatePrecision sharing per ADR-039/040) instead of a novel mechanism for a solved problem?
+7. Are domain terms used per [docs/GLOSSARY.md](../../docs/GLOSSARY.md), keeping the ubiquitous language consistent?
+8. Is the blast radius bounded — does the change avoid forcing edits across unrelated domains, or is the coupling explicitly justified?
+9. Does the data model choose the right precision/constraint level deliberately (e.g. NOT NULL audit fields, CHECK constraints) rather than by default, and is the choice recorded?
+10. Does the spec keep `Person`/`AppUser` (and other established separations) distinct?
+11. Are non-functional consequences (performance of the lazy-fetch path, N+1 risk, index needs) named in `design.md`?
+12. Does `design.md` list the alternatives considered and why they were rejected, not just the chosen path?
+
+## EARS patterns to watch for
+
+- **Ubiquitous** requirements (`The <system> shall <invariant>`) encode architectural invariants — confirm each invariant is enforced at the right layer (DB CHECK, service guard, or type) and not merely asserted in prose.
+- **Optional-feature** requirements signal a new seam/extension point — verify it does not become an unbounded plugin surface without an ADR.
+- Watch for requirements that imply a second source of truth for data that already has an owning domain.
+
+## Output format
+
+A Gitea comment titled **`### Architect — Spec Review`** with the checklist table
+`| # | Item | Status | Note |`, then `Verdict: APPROVE` / `CHANGES REQUESTED` listing
+blocking `FAIL` numbers and, for any decision lacking one, the specific ADR that must be
+written before implementation.

.specify/personas/developer.md

@@ -0,0 +1,39 @@
+# Persona — Developer (spec review)
+
+> Concise spec-review checklist. Full character persona:
+> [`.claude/personas/developer.md`](../../.claude/personas/developer.md). This file gates a
+> `spec.md` for implementability against the real codebase.
+
+## Role summary
+
+I check that a spec can actually be built in *this* codebase without fighting its
+architecture: that it reuses existing services, layers, and error machinery, and that its
+requirements decompose cleanly into red/green TDD tasks. I block specs that invent parallel
+structures or hand-wave the hard integration points.
+
+## Review checklist (PASS / FAIL / QUESTION per item)
+
+1. Does the spec reference existing service interfaces (e.g. `DocumentService`, `FileService`, `UserService`) rather than inventing new ones inconsistent with the current layer structure?
+2. Does it respect the layering rule — no requirement implies a controller touching a repository or a service reaching into another domain's repository?
+3. If it adds a backend domain, does it commit to adding the package to `ArchitectureTest`'s allow-lists?
+4. Are new error conditions expressed as named `ErrorCode`s, with the four-site update (`ErrorCode.java`, `errors.ts`, `getErrorMessage()`, `messages/{de,en,es}.json`) called out as tasks?
+5. Does every entity/DTO field the spec adds get `@Schema(requiredMode = REQUIRED)` where always-populated, and is `npm run generate:api` listed as a task after backend changes?
+6. Are frontend changes inside the correct `$lib/<domain>/` boundary, with any cross-domain import either pre-allowed in `eslint.config.js` or flagged for an explicit allow-entry?
+7. Does each `REQ-NNN` imply a concrete test at the right level (unit / `@WebMvcTest` slice / Playwright E2E per COLLABORATING.md's table) — i.e. is it specified concretely enough to write that test?
+8. Is lazy-loading handled — does any returned entity with a lazy collection get a view (ADR-036) instead of being serialized raw?
+9. Does the design avoid premature abstraction (KISS over DRY) — no new base class/util introduced before a third caller exists?
+10. Are data-model changes expressed as a single forward-only Flyway migration with the next free `V<n>` number verified against disk?
+11. Does the spec avoid backwards-compat shims for code paths that have no existing callers?
+12. Are the requirements decomposable into a red/green-ordered task list — each behavior small enough that a failing test can precede its implementation?
+
+## EARS patterns to watch for
+
+- **Event-driven** requirements must name the exact endpoint/method so the test target is unambiguous (`When POST /api/users/{id}/avatar receives a valid image, the user service shall …`).
+- **Unwanted-behavior** requirements are the ones that become `@WebMvcTest` error-path cases — flag any that lack a stated `ErrorCode` and HTTP status.
+- **Optional-feature** (`Where …`) requirements map to a `@RequirePermission` gate — confirm the permission already exists or is added.
+
+## Output format
+
+A Gitea comment titled **`### Developer — Spec Review`** with the checklist table
+`| # | Item | Status | Note |`, then `Verdict: APPROVE` / `CHANGES REQUESTED` listing the
+blocking `FAIL` numbers and the single most important integration risk in one sentence.

.specify/personas/devops.md

@@ -0,0 +1,39 @@
+# Persona — DevOps (spec review)
+
+> Concise spec-review checklist. Full character persona:
+> [`.claude/personas/devops.md`](../../.claude/personas/devops.md). This file gates a
+> `spec.md` for deployability, migration safety, and CI/observability impact.
+
+## Role summary
+
+I check that a feature can ship to the self-hosted Gitea-Actions / Docker-Compose
+environment without breaking deploys, migrations, or observability. I block specs that add
+a migration with no rollback story, a new env var nobody documented, or a CI step that the
+act_runner cannot execute.
+
+## Review checklist (PASS / FAIL / QUESTION per item)
+
+1. Does the spec include a rollback strategy for any database migration it introduces (forward-only `V<n>` plus the manual DDL to reverse it, or an explicit "no rollback, forward-fix only" statement)?
+2. Is the Flyway migration number the next free `V<n>` verified against disk, not copied from a stale issue body?
+3. Are all new configuration values introduced as documented env vars (added to `.env.example`) and read via env, never hard-coded?
+4. Does any new CI step avoid `actions/(upload|download)-artifact@v4+` and other features the Gitea `act_runner` does not support?
+5. If the spec adds a CI guard, is it self-testing (the regex proves it catches the bad form and ignores the good form), matching the existing guard style?
+6. Does the feature keep the management port (`8081`) / app port (`8080`) separation intact, and not require Caddy to proxy `/actuator/*`?
+7. Are new dependencies pinned, and does the change keep `npm audit --audit-level=high` and Semgrep green?
+8. Does a new external service or sidecar come with a healthcheck and a documented Compose entry, and is bucket/bootstrap logic idempotent (re-deploy must not fail)?
+9. Are new metrics/logs/traces routed through the existing observability stack (Prometheus scrape, Promtail/Loki, Tempo, GlitchTip) rather than a new ad-hoc channel?
+10. Does logging added by the feature stay PII-free and structured (JSON), consistent with the existing log pipeline?
+11. Is the feature backwards-compatible across a rolling deploy, or does the spec state the required downtime/ordering (migrate-then-deploy)?
+12. Does the spec avoid committing secrets, and does any composite-action secret flow follow the unquoted-heredoc env convention (ADR-029)?
+
+## EARS patterns to watch for
+
+- **State-driven** (`While a migration is in progress, the system shall …`) and **Unwanted-behavior** (`If the OCR service is unavailable, then the system shall return OCR_SERVICE_UNAVAILABLE`) requirements encode operational resilience — flag mutating/processing features that lack them.
+- **Optional-feature** (`Where the observability stack is enabled …`) requirements gate optional infra — confirm the feature degrades cleanly when it is off.
+
+## Output format
+
+A Gitea comment titled **`### DevOps — Spec Review`** with the checklist table
+`| # | Item | Status | Note |`, then `Verdict: APPROVE` / `CHANGES REQUESTED` listing
+blocking `FAIL` numbers, with the migration/rollback line called out explicitly when
+relevant.

.specify/personas/requirements-engineer.md

@@ -0,0 +1,43 @@
+# Persona — Requirements Engineer (spec review)
+
+> Concise spec-review checklist. The full character persona (used for issue/PR review via
+> the `review-issue` / `review-pr` skills) lives at
+> [`.claude/personas/req_engineer.md`](../../.claude/personas/req_engineer.md). This file is
+> scoped to one job: gate a `spec.md` before implementation starts.
+
+## Role summary
+
+I own requirement quality: every requirement must be atomic, testable, uniquely identified,
+and written in EARS so an engineer and an AI agent read it the same way. I block specs that
+are ambiguous, unmeasurable, or untraceable — vague requirements become vague code.
+
+## Review checklist (PASS / FAIL / QUESTION per item)
+
+1. Does every requirement have a unique zero-padded `REQ-NNN` ID, scoped to this feature?
+2. Is every requirement written in one of the five EARS patterns (no free-prose "shall" sentences)?
+3. Is each requirement atomic — exactly one testable behavior, no "and"-joined clauses hiding two requirements?
+4. Does every requirement name a concrete system actor (e.g. `the document service`, `the upload form`) rather than a vague "system"?
+5. Does each `REQ-NNN` have at least one matching, **measurable** acceptance criterion (numbers/limits, not adjectives like "fast" or "user-friendly")?
+6. Are all five EARS patterns considered, and is each used where appropriate (not every requirement forced into Ubiquitous)?
+7. Is there an Unwanted-behavior (`If …`) requirement for every error, limit, and rejected input the happy path implies?
+8. Does the `## Out of Scope` section explicitly fence off the nearest tempting scope creep?
+9. Are all `## Open Questions` resolved (or explicitly deferred with an owner) — none left as silent blockers?
+10. Does the spec link the constitution principle(s) it depends on in `## Context & Why`?
+11. Is every `REQ-NNN` present in `.specify/rtm.md` with a Feature, Test, and Status column filled (even if Status = Planned)?
+12. Does the spec reuse existing domain vocabulary from [docs/GLOSSARY.md](../../docs/GLOSSARY.md) (e.g. Person vs AppUser, Chronik vs Aktivität) rather than inventing terms?
+13. Are the User Journey and E2E Scenarios (per COLLABORATING.md) present and consistent with the EARS requirements?
+
+## EARS patterns to watch for (common violations)
+
+- **Ubiquitous** — `The <system> shall <behavior>.` Violation: an invariant written as prose with no "shall".
+- **Event-driven** — `When <trigger>, the <system> shall <behavior>.` Violation: a trigger described but the response left implicit.
+- **State-driven** — `While <state>, the <system> shall <behavior>.` Violation: a state precondition buried inside an Event-driven clause.
+- **Optional-feature** — `Where <feature is present>, the <system> shall <behavior>.` Violation: a permission-/flag-gated behavior written as Ubiquitous, so it appears mandatory.
+- **Unwanted-behavior** — `If <undesired condition>, then the <system> shall <response>.` Violation: missing entirely — the single most common gap. Every limit and rejected input needs one.
+
+## Output format
+
+A Gitea comment titled **`### Requirements Engineer — Spec Review`** containing the
+checklist as a table `| # | Item | Status | Note |` with `PASS` / `FAIL` / `QUESTION` per
+row, then a short verdict line: `Verdict: APPROVE` or `Verdict: CHANGES REQUESTED` with the
+blocking `FAIL` numbers listed.

.specify/personas/security.md

@@ -0,0 +1,42 @@
+# Persona — Security (spec review)
+
+> Concise spec-review checklist. Full character persona (Nora "NullX" Steiner):
+> [`.claude/personas/security_expert.md`](../../.claude/personas/security_expert.md). This
+> file gates a `spec.md` and its `threat-model.md` before implementation.
+
+## Role summary
+
+I read every spec adversarially: I assume the requirement will be hit by an unauthenticated
+attacker, a logged-in user attacking another user's data, and malicious input. I block specs
+whose mutating endpoints, file handling, or audit trails leave a hole that the happy-path
+requirements never mention.
+
+## Review checklist (PASS / FAIL / QUESTION per item)
+
+1. Are **all** state-mutating endpoints (`POST/PUT/PATCH/DELETE`) covered by an Unwanted-behavior EARS clause for unauthenticated **and** unauthorized access, each naming the `Permission` and the response code?
+2. Does every mutating endpoint name the `@RequirePermission(Permission.X)` it will carry — and is that permission the least privilege that works?
+3. Are audit fields (`createdBy`/`updatedBy`) specified as server-set from the session principal, with an explicit requirement forbidding them in the request body (mass-assignment / authorship-forgery, CWE-639)?
+4. Is every IDOR surface addressed — does fetching/mutating a child resource verify it belongs to the caller's accessible parent (e.g. JourneyItem → Geschichte), with a requirement and a test?
+5. Is all untrusted text (user input, OCR/import-derived) specified to render via default escaping, never `{@html}` (CWE-79)?
+6. For file uploads: are content-type allow-list, size limit, and magic-byte/extension validation specified as requirements with concrete numbers and an `ErrorCode`?
+7. Does the spec avoid leaking entity internals (email, password hash, group graph) in any response — i.e. does it use a view, not a raw `AppUser`/entity?
+8. Are concurrency conflicts (optimistic locking) specified to surface as `conflict()` (409), never a raw 500 exposing Hibernate internals (CWE-209)?
+9. Does the `threat-model.md` exist and cover the relevant STRIDE categories for each new data flow and trust boundary?
+10. If the feature invokes an AI agent/tool (OCR/NLP/LLM), does the threat model cover the ASTRIDE extensions (prompt injection, context poisoning, unsafe tool invocation, reasoning subversion)?
+11. Are secrets (tokens, DSNs, passwords) sourced only from env vars, with none introduced into the repo, config, or logs?
+12. Does logging for this feature exclude PII beyond a stable UUID (no names, emails, document/transcription content)?
+13. Does a new runtime dependency (if any) have an ADR and a clean `npm audit` / Semgrep status?
+
+## EARS patterns to watch for
+
+- The **Unwanted-behavior** pattern (`If <attacker condition>, then the <system> shall <safe response>`) is *the* security pattern. Every auth, authz, validation, and limit case must appear as one. A spec with zero `If` requirements on a mutating endpoint is an automatic `FAIL`.
+- **Optional-feature** (`Where the caller has Permission.X …`) requirements encode the authorization model — verify the gate is on the *write*, not just the read.
+- Watch for **Ubiquitous** requirements that quietly assume trust ("The system shall store the uploaded file") with no companion `If` clause validating it first.
+
+## Output format
+
+A Gitea comment titled **`### Security — Spec Review`** with the checklist table
+`| # | Item | Status | Note |`, each `FAIL` tagged with its CWE where applicable, then
+`Verdict: APPROVE` / `CHANGES REQUESTED` listing blocking `FAIL` numbers. Security `FAIL`s
+are hard blockers — a spec does not proceed until each is resolved or risk-accepted in the
+threat model.

.specify/personas/ui-ux.md

@@ -0,0 +1,39 @@
+# Persona — UI/UX (spec review)
+
+> Concise spec-review checklist. Full character persona:
+> [`.claude/personas/ui_expert.md`](../../.claude/personas/ui_expert.md). This file gates a
+> `spec.md` for user-facing features against the project's design system and audience split.
+
+## Role summary
+
+I check that a user-facing feature is usable by *this* audience — older transcribers on
+laptops/tablets and younger readers on phones — and that it uses the established design
+tokens, components, and i18n rather than reinventing them. I block specs whose UI is
+described in adjectives instead of states, or that ignore accessibility and responsiveness.
+
+## Review checklist (PASS / FAIL / QUESTION per item)
+
+1. Does the spec describe every interaction **state** (loading, empty, error, success, disabled), not just the happy path?
+2. Are user-facing strings specified to go through Paraglide i18n with keys added to `messages/{de,en,es}.json` — no hard-coded German/English literals?
+3. Does it reuse the established component library and patterns (`BackButton`, the card pattern, `brand-navy`/`brand-mint` tokens, `font-serif`/`font-sans`) rather than introducing new one-off styles?
+4. Is the responsive behavior specified per the device split — Critical for the reader/phone path, at least Minor for the author/laptop path — with concrete breakpoints, not "responsive"?
+5. Are error states mapped to `getErrorMessage(code)` output so the user sees a localized message, never a raw code or stack?
+6. Is every interactive element keyboard-reachable and screen-reader-labeled (the project runs `@axe-core/playwright`)?
+7. Are acceptance criteria measurable (e.g. "image preview appears within 1 of selection", "tap target ≥ 44px"), not adjectival ("looks clean")?
+8. Does the spec define an E2E Playwright scenario (per COLLABORATING.md) for each primary user journey step?
+9. For destructive or irreversible actions, is a confirmation/undo affordance specified?
+10. Does any uploaded/derived content render through default escaping (no `{@html}`), and are images given alt text / dimensions to avoid layout shift?
+11. Does the feature respect existing navigation (live DOM nav, real routes — verify route names against the running app, since CLAUDE.md route lists can be stale)?
+12. Is dark-mode / token theming respected (uses semantic tokens like `bg-surface`/`text-ink-3`, not raw palette constants)?
+
+## EARS patterns to watch for
+
+- **State-driven** (`While the upload is in progress, the upload form shall show a progress indicator`) requirements capture UI states — a UI spec with no `While` requirements usually means the loading/disabled states were forgotten.
+- **Event-driven** (`When the user selects an image, the form shall render a preview`) requirements map directly to Playwright steps — confirm each has a measurable acceptance criterion.
+- **Unwanted-behavior** (`If the selected file exceeds the size limit, then the form shall show a localized error and not upload`) requirements cover client-side validation feedback.
+
+## Output format
+
+A Gitea comment titled **`### UI/UX — Spec Review`** with the checklist table
+`| # | Item | Status | Note |`, then `Verdict: APPROVE` / `CHANGES REQUESTED` listing
+blocking `FAIL` numbers and the single biggest usability/accessibility gap in one sentence.

.specify/rtm.md

@@ -0,0 +1,108 @@
+# Requirements Traceability Matrix (RTM)
+
+> Living document. One row per `REQ-NNN` across all in-flight and shipped features. The spec
+> itself lives in the **Gitea issue** (issue-only — there is no committed `spec.md`); this
+> matrix is the part of the spec that *is* committed: it links each requirement to its issue,
+> the code that implements it, and the test(s) that prove it — so any requirement traces end
+> to end, and any orphan (a requirement with no test) is visible on `main`.
+
+## How to update
+
+1. When a feature's issue is approved (via `/review-issue`), add one row per `REQ-NNN` with the
+   `Issue` set to the Gitea issue number and `Status: Planned`. Commit these rows on the feature
+   branch (they merge with the feature's PR).
+2. As tasks land, fill `Implementation File(s)` + `Test(s)` and flip `Status` →
+   `In progress` → `Done`.
+3. `REQ-ID`s are **scoped per feature**, so always read them together with the `Issue` column —
+   `REQ-001` for issue #142 is not `REQ-001` for issue #150.
+4. The `sdd-gate.yml` CI job (`rtm-check`) warns (non-blocking, for now) when a row is missing
+   its `Issue` or `Test(s)`. It flips to blocking once adoption settles (see the workflow's TODO).
+
+## Status legend
+
+`Planned` · `In progress` · `Done` · `Deferred`
+
+## Matrix
+
+| REQ-ID | Requirement Summary | Issue | Feature | Implementation File(s) | Test(s) | Status |
+|---|---|---|---|---|---|---|
+| REQ-001 | Store avatar at `avatars/{userId}`, overwrite | #example | profile-picture-upload (_example) | `UserService` (planned) | `UserServiceAvatarTest#storesUnderUserKey`, `#replaceLeavesNoOrphan` | Planned |
+| REQ-002 | Upload self avatar → 200 + avatarUrl | #example | profile-picture-upload (_example) | `UserAvatarController`, `UserService` (planned) | `UserAvatarControllerTest#uploadReturnsAvatarUrl` | Planned |
+| REQ-003 | Delete self avatar → avatarUrl null | #example | profile-picture-upload (_example) | `UserAvatarController` (planned) | `UserAvatarControllerTest#deleteClearsAvatar` | Planned |
+| REQ-004 | No avatar → null + initials placeholder | #example | profile-picture-upload (_example) | `UserProfileView`, avatar component (planned) | `avatar-placeholder.svelte.spec.ts` | Planned |
+| REQ-005 | ADMIN_USER may delete others' avatar | #example | profile-picture-upload (_example) | `UserAvatarController` (planned) | `UserAvatarControllerTest#adminDeletesOthersAvatar` | Planned |
+| REQ-006 | Unauthenticated → 401, store nothing | #example | profile-picture-upload (_example) | `SecurityConfig`, controller (planned) | `UserAvatarControllerTest#unauthenticatedReturns401` | Planned |
+| REQ-007 | Non-image → 400 UNSUPPORTED_FILE_TYPE | #example | profile-picture-upload (_example) | `UserService` (planned) | `UserAvatarControllerTest#rejectsNonImage` | Planned |
+| REQ-008 | Over 2 MB → 400 AVATAR_TOO_LARGE | #example | profile-picture-upload (_example) | `UserService`, `ErrorCode` (planned) | `UserAvatarControllerTest#rejectsOversize` | Planned |
+| REQ-009 | Non-admin on others → 403 FORBIDDEN | #example | profile-picture-upload (_example) | `UserAvatarController` (planned) | `UserAvatarControllerTest#nonAdminForbiddenOnOthers` | Planned |
+| REQ-001 | Render dated entry via shared `formatDocumentDate` (de/en/es) | #778 | timeline-date-label | `frontend/src/lib/timeline/dateLabel.ts` | `dateLabel.spec.ts` › `renders a DAY date localized in German`, `renders a SEASON date with the German season word`, `delegates a same-year RANGE to formatDocumentDate` | Done |
+| REQ-002 | Non-UNKNOWN + non-empty date → shared label, `raw=null`, `getLocale()` | #778 | timeline-date-label | `frontend/src/lib/timeline/dateLabel.ts` | `dateLabel.spec.ts` › `renders a DAY date localized in German`, `renders a DAY date localized in English` | Done |
+| REQ-003 | `UNKNOWN` → `null` (no chip) | #778 | timeline-date-label | `frontend/src/lib/timeline/dateLabel.ts` | `dateLabel.spec.ts` › `returns null for UNKNOWN precision even with a date`, `returns null for UNKNOWN precision without a date` | Done |
+| REQ-004 | `null`/`undefined`/`''` eventDate → `null`, no formatter call | #778 | timeline-date-label | `frontend/src/lib/timeline/dateLabel.ts` | `dateLabel.spec.ts` › `returns null for APPROX with a null eventDate, without calling the formatter`, `returns null for DAY with an empty-string eventDate`, `treats undefined eventDateEnd identically to null for RANGE` | Done |
+| REQ-005 | No rendering logic outside `documentDate.ts` | #778 | timeline-date-label | `frontend/src/lib/timeline/dateLabel.ts` (façade) | `dateLabel.spec.ts` › `delegates a same-year RANGE to formatDocumentDate` (asserts byte-identical delegation) | Done |
+| REQ-006 | `timeline` in coverage `include` (80% branch gate) | #778 | timeline-date-label | `frontend/vite.config.ts` | coverage `include` now lists `src/lib/timeline/**`; covered by all `dateLabel.spec.ts` cases | Done |
+
+<!-- Append real features below this line, one row per REQ-NNN, with the real issue number. Keep the header row above. -->
+| REQ-001 | family-member Person with birthDate → 1 BIRTH event, precision passed through | #776 | derive-person-life-events | `timeline/TimelineEventService#buildBirthEvents` | `DerivedEventsAssemblyTest#should_emit_one_geburt_for_person_with_birthdate`, `#should_pass_birth_precision_through_unchanged` | Done |
+| REQ-002 | family-member Person with deathDate → 1 DEATH event | #776 | derive-person-life-events | `timeline/TimelineEventService#buildDeathEvents` | `DerivedEventsAssemblyTest#should_emit_one_tod_for_person_with_deathdate`, `#should_emit_one_tod_and_zero_geburt_for_person_with_deathdate_only` | Done |
+| REQ-003 | null birthDate → 0 Geburt events | #776 | derive-person-life-events | `timeline/TimelineEventService#buildBirthEvents` | `DerivedEventsAssemblyTest#should_emit_zero_tod_when_person_has_birthdate_but_no_deathdate`, `#should_emit_one_tod_and_zero_geburt_for_person_with_deathdate_only` | Done |
+| REQ-004 | null deathDate → 0 Tod events; no dates → 0 events | #776 | derive-person-life-events | `timeline/TimelineEventService#buildDeathEvents` | `DerivedEventsAssemblyTest#should_emit_no_events_for_person_with_neither_date` | Done |
+| REQ-005 | SPOUSE_OF edge with fromYear → MARRIAGE event, eventDate={fromYear}-01-01, precision=YEAR | #776 | derive-person-life-events | `timeline/TimelineEventService#buildMarriageEvents` | `DerivedEventsAssemblyTest#should_emit_one_heirat_for_spouse_edge_with_fromYear` | Done |
+| REQ-006 | SPOUSE_OF edge with null fromYear → MARRIAGE emitted, eventDate=null, precision=UNKNOWN | #776 | derive-person-life-events | `timeline/TimelineEventService#buildMarriageEvents` | `DerivedEventsAssemblyTest#should_emit_unknown_precision_heirat_when_fromYear_is_null` | Done |
+| REQ-007 | exactly one MARRIAGE per SPOUSE_OF row (dedup on relationship id) | #776 | derive-person-life-events | `timeline/TimelineEventService#buildMarriageEvents` | `DerivedEventsAssemblyTest#should_emit_exactly_one_heirat_when_both_spouses_in_scope`, `#should_emit_two_heirat_for_person_married_to_two_partners` | Done |
+| REQ-008 | synthetic prefixed ids (birth:/death:/marriage:), never parseable as UUID | #776 | derive-person-life-events | `timeline/TimelineEventService#buildBirthEvents,#buildDeathEvents,#buildMarriageEvents` | `DerivedEventsAssemblyTest#should_mint_prefixed_synthetic_ids_never_uuid` | Done |
+| REQ-009 | every derived event: derived=true, type=PERSONAL, non-null derivedType, non-UUID id | #776 | derive-person-life-events | `timeline/TimelineEventService` | structural invariants asserted inline in every event test | Done |
+| REQ-010 | every derived event: non-null non-blank primaryPersonName; Heirat also non-null non-blank relatedPersonName | #776 | derive-person-life-events | `timeline/TimelineEventService#buildBirthEvents,#buildDeathEvents,#buildMarriageEvents` | `DerivedEventsAssemblyTest#should_emit_heirat_with_displayname_for_both_spouses` | Done |
+| REQ-011 | exactly one call to findAllFamilyMembers() and one to findAllSpouseEdges() — no N+1 | #776 | derive-person-life-events | `timeline/TimelineEventService#assembleDerivedEvents`, `relationship/RelationshipService#findAllSpouseEdges` | test structure: only batch-fetch mocks used (no per-person stubs) | Done |
+| REQ-012 | familyMember=false persons excluded from Geburt/Tod assembly | #776 | derive-person-life-events | `timeline/TimelineEventService#assembleDerivedEvents` (via PersonService.findAllFamilyMembers) | `DerivedEventsAssemblyTest#should_exclude_non_family_member_persons_from_derived_events` | Done |
+| REQ-013 | SPOUSE_OF edge with one non-family-member spouse still emits 1 MARRIAGE event | #776 | derive-person-life-events | `timeline/TimelineEventService#buildMarriageEvents` | `DerivedEventsAssemblyTest#should_emit_heirat_when_one_spouse_is_not_family_member` | Done |
+| REQ-014 | empty family-member list → empty result, no error | #776 | derive-person-life-events | `timeline/TimelineEventService#assembleDerivedEvents` | `DerivedEventsAssemblyTest#should_emit_zero_events_when_no_family_members` | Done |
+| REQ-015 | assembleDerivedEvents() annotated @Transactional(readOnly=true) | #776 | derive-person-life-events | `timeline/TimelineEventService#assembleDerivedEvents` | code-review check (annotation visible in source) | Done |
+| REQ-016 | no PII (names, dates) in log statements — only aggregate counts | #776 | derive-person-life-events | `timeline/TimelineEventService#assembleDerivedEvents` | log-audit: single log.debug with result.size() and persons.size() only | Done |
+| REQ-001 | GET /api/timeline requires READ_ALL permission; 401 unauthenticated, 403 wrong permission | #777 | timeline-assembly | `timeline/TimelineController#getTimeline` | `TimelineControllerTest#returns_401_when_unauthenticated`, `#returns_403_when_authenticated_without_read_all`, `#returns_200_with_read_all_permission` | Done |
+| REQ-002 | within-band sort: precision rank desc (DAY>MONTH>SEASON>YEAR>APPROX), then date asc, then title alpha, then id tiebreak | #777 | timeline-assembly | `timeline/TimelineService#WITHIN_BAND_ORDER` | `TimelineServiceTest#within_band_order_day_precision_sorts_before_year`, `#within_band_order_same_precision_and_date_sorts_alphabetically`, `#within_band_order_same_title_uses_document_id_as_tiebreak`, `#test5_day_precision_sorts_before_year_in_same_year_band`, `#test6_same_precision_same_date_sorted_alphabetically_by_title` | Done |
+| REQ-003 | null eventDate OR UNKNOWN precision → undated bucket (never in a year band) | #777 | timeline-assembly | `timeline/TimelineService#bucketByYear` | `TimelineServiceTest#test3a_null_date_letter_goes_to_undated`, `#test3b_unknown_precision_letter_goes_to_undated` | Done |
+| REQ-004 | RANGE events placed in start-year band only; null eventDateEnd does not crash; start year outside [fromYear,toYear] → excluded | #777 | timeline-assembly | `timeline/TimelineService#assembleCuratedEvents` | `TimelineServiceTest#test7a_range_event_placed_only_in_start_year_band`, `#test7b_range_event_with_null_eventDateEnd_does_not_crash`, `#test8_range_event_excluded_when_start_year_before_fromYear`, `#test15_range_event_start_year_equal_to_fromYear_is_included` | Done |
+| REQ-005 | null sender and null senderText on a document → senderName="" in the TimelineEntryDTO | #777 | timeline-assembly | `timeline/TimelineService#toLetterEntry` | `TimelineServiceTest#test4_letter_with_null_sender_and_null_senderText_produces_empty_names` | Done |
+| REQ-006 | personId filter: include document when personId is sender OR receiver | #777 | timeline-assembly | `timeline/TimelineService#fetchDocuments` | `TimelineServiceTest#test11_personId_scoping_deduplicates_letter_appearing_as_sender_and_receiver` | Done |
+| REQ-007 | documents domain letters always included (no type filter applied to LETTER kind) | #777 | timeline-assembly | `timeline/TimelineService#fetchDocuments`, `#assemble` | `TimelineServiceTest#test9a_type_filter_does_not_exclude_letters_but_excludes_wrong_type_events`, `#test1_empty_archive_returns_empty_dto`, `#test2_one_year_letter_returns_one_year_band` | Done |
+| REQ-008 | personId filter dedup: sender+receiver same person → document appears exactly once | #777 | timeline-assembly | `timeline/TimelineService#fetchDocuments` | `TimelineServiceTest#test11_personId_scoping_deduplicates_letter_appearing_as_sender_and_receiver` | Done |
+| REQ-009 | type filter applies to events only; letters (LETTER kind) always pass | #777 | timeline-assembly | `timeline/TimelineService#assembleCuratedEvents`, `#assembleDerivedEventsLayer` | `TimelineServiceTest#test9a_type_filter_does_not_exclude_letters_but_excludes_wrong_type_events` | Done |
+| REQ-010 | generation filter: PersonService.getPersonsByGeneration(N) used to build person-id set; filters all three layers | #777 | timeline-assembly | `timeline/TimelineService#assemble`, `person/PersonService#getPersonsByGeneration`, `person/PersonRepository#findByGeneration` | `TimelineServiceTest#test9b_generation_filter_includes_letter_when_sender_matches_generation`, `TimelineServiceIntegrationTest#findByGeneration_returns_matching_persons`, `#findByGeneration_returns_empty_list_not_npe_when_no_match`, `#findByGeneration_does_not_return_null_generation_persons` | Done |
+| REQ-011 | fromYear/toYear inclusive year-range filter; single-year window (fromYear==toYear); one-sided filter (fromYear only) | #777 | timeline-assembly | `timeline/TimelineService#passesYearFilter` | `TimelineServiceTest#test9c_fromYear_toYear_inclusive_single_year_window`, `#test16_fromYear_without_toYear_returns_all_items_from_that_year_onwards` | Done |
+| REQ-012 | combined filters AND logic — entry must pass all active filters | #777 | timeline-assembly | `timeline/TimelineService#assemble` | `TimelineServiceTest#test10_adversarial_and_logic_neither_event_passes_both_filters`, `#test12_personId_plus_generation_filter_returns_empty_when_generations_do_not_match` | Done |
+| REQ-013 | empty archive (no events, no persons, no documents) → TimelineDTO { years=[], undated=[] } | #777 | timeline-assembly | `timeline/TimelineService#assemble` | `TimelineServiceTest#test1_empty_archive_returns_empty_dto` | Done |
+| REQ-014 | unauthenticated request → 401 Unauthorized | #777 | timeline-assembly | `timeline/TimelineController#getTimeline` | `TimelineControllerTest#returns_401_when_unauthenticated` | Done |
+| REQ-015 | authenticated without READ_ALL → 403 Forbidden | #777 | timeline-assembly | `timeline/TimelineController#getTimeline` | `TimelineControllerTest#returns_403_when_authenticated_without_read_all` | Done |
+| REQ-016 | fromYear > toYear → 400 Bad Request | #777 | timeline-assembly | `timeline/TimelineService#assemble` | `TimelineServiceTest#fromYear_greater_than_toYear_throws_bad_request`, `TimelineControllerTest#returns_400_when_fromYear_greater_than_toYear` | Done |
+| REQ-017 | generation < 0 → 400 Bad Request (@Min(0) on controller param) | #777 | timeline-assembly | `timeline/TimelineController#getTimeline` | `TimelineControllerTest#returns_400_when_generation_is_negative` | Done |
+| REQ-018 | unknown EventType string → 400 Bad Request (Spring enum binding) | #777 | timeline-assembly | `timeline/TimelineController#getTimeline` | `TimelineControllerTest#returns_400_on_bad_type_value` | Done |
+| REQ-019 | unknown personId → 404 Not Found | #777 | timeline-assembly | `timeline/TimelineService#assemble` | `TimelineControllerTest#returns_404_when_person_not_found` | Done |
+| REQ-020 | null-generation persons excluded from generation-filter results | #777 | timeline-assembly | `person/PersonRepository#findByGeneration` | `TimelineServiceTest#test13_null_generation_sender_not_returned_by_generation_filter`, `TimelineServiceIntegrationTest#findByGeneration_does_not_return_null_generation_persons` | Done |
+| REQ-001 | `/zeitstrahl` renders the global timeline for authenticated users, personId undefined | #779 | zeitstrahl-global-view | `frontend/src/routes/zeitstrahl/+page.server.ts`, `+page.svelte` | `zeitstrahl/page.server.test.ts#fetches GET /api/timeline and returns { timeline } on ok` | Done |
+| REQ-002 | server-load fetches GET /api/timeline via createApiClient, returns { timeline }, no client fetch | #779 | zeitstrahl-global-view | `frontend/src/routes/zeitstrahl/+page.server.ts` | `zeitstrahl/page.server.test.ts#fetches GET /api/timeline and returns { timeline } on ok` | Done |
+| REQ-003 | render bands + entries in DTO order, no client re-sort/re-bucket | #779 | zeitstrahl-global-view | `frontend/src/lib/timeline/YearBand.svelte`, `TimelineView.svelte` | `YearBand.svelte.spec.ts#renders entries in DTO order`, `TimelineView.svelte.spec.ts#renders the timeline as a single <ol>` | Done |
+| REQ-004 | ≥1024px centered axis, letters alternating left/right | #779 | zeitstrahl-global-view | `frontend/src/lib/timeline/YearBand.svelte` (data-side CSS), `TimelineView.svelte` | `TimelineView.svelte.spec.ts#places consecutive letter cards on alternating sides`, `e2e/zeitstrahl.spec.ts` | Done |
+| REQ-005 | <1024px single left axis, no overflow down to 320px | #779 | zeitstrahl-global-view | `frontend/src/lib/timeline/YearBand.svelte`, `LetterCard.svelte` | `e2e/zeitstrahl.spec.ts#no horizontal overflow at 320px with long correspondent names` | Done |
+| REQ-006 | single `<ol>` chronological; each band a `<section>` with sticky `<h2>` at top:4rem | #779 | zeitstrahl-global-view | `frontend/src/lib/timeline/TimelineView.svelte`, `YearBand.svelte` | `TimelineView.svelte.spec.ts#renders the timeline as a single <ol>`, `YearBand.svelte.spec.ts#sticky h2 at top:4rem` | Done |
+| REQ-007 | derived entry → centered family pill with glyph + German derivedType label | #779 | zeitstrahl-global-view | `frontend/src/lib/timeline/EventPill.svelte`, `eventCardConfig.ts` | `EventPill.svelte.spec.ts#derived marriage/birth/death`, `eventCardConfig.spec.ts` | Done |
+| REQ-008 | curated PERSONAL pill; edit affordance only when eventId != null | #779 | zeitstrahl-global-view | `frontend/src/lib/timeline/EventPill.svelte` | `EventPill.svelte.spec.ts#edit affordance for curated with eventId`, `#no edit affordance when eventId is null`, `#no edit affordance for a derived event` | Done |
+| REQ-009 | HISTORICAL → full-width band once in eventDate year; RANGE span pill with Zeitraum aria-label | #779 | zeitstrahl-global-view | `frontend/src/lib/timeline/WorldBand.svelte` | `WorldBand.svelte.spec.ts#RANGE span pill 1914–1918 with a Zeitraum aria-label` | Done |
+| REQ-010 | RANGE with null eventDateEnd → start-year label, no span pill, no crash | #779 | zeitstrahl-global-view | `frontend/src/lib/timeline/WorldBand.svelte` | `WorldBand.svelte.spec.ts#degrades a RANGE with no end to the start year` | Done |
+| REQ-011 | band ≤12 letters → individual LetterCards | #779 | zeitstrahl-global-view | `frontend/src/lib/timeline/YearBand.svelte` | `YearBand.svelte.spec.ts#renders each letter as a card`, `TimelineView.svelte.spec.ts` | Done |
+| REQ-012 | band >12 letters → single YearLetterStrip with count + 12-month sparkline + expand toggle | #779 | zeitstrahl-global-view | `frontend/src/lib/timeline/YearLetterStrip.svelte`, `timelineDensity.ts` | `YearLetterStrip.svelte.spec.ts`, `YearBand.svelte.spec.ts#renders a single strip`, `timelineDensity.spec.ts#isDense` | Done |
+| REQ-013 | every dated entry renders date via timelineDateLabel; null → no chip | #779 | zeitstrahl-global-view | `frontend/src/lib/timeline/LetterCard.svelte` | `LetterCard.svelte.spec.ts#renders the precision date exactly`, `#renders no date chip when timelineDateLabel returns null` | Done |
+| REQ-014 | empty senderName/receiverName → "Unbekannt" placeholder, never a bare arrow | #779 | zeitstrahl-global-view | `frontend/src/lib/timeline/LetterCard.svelte` | `LetterCard.svelte.spec.ts#shows "Unbekannt" for an empty sender`, `#empty receiver` | Done |
+| REQ-015 | interior empty-year run → one folded GapSpan (single year if length 1) | #779 | zeitstrahl-global-view | `frontend/src/lib/timeline/TimelineView.svelte`, `GapSpan.svelte` | `TimelineView.svelte.spec.ts#folds an interior run of empty years`, `#single empty interior year`, `GapSpan.svelte.spec.ts` | Done |
+| REQ-016 | undated non-empty → final "Ohne Datum" section; empty → absent from DOM | #779 | zeitstrahl-global-view | `frontend/src/lib/timeline/TimelineView.svelte` | `TimelineView.svelte.spec.ts#renders an "Ohne Datum" section`, `#omits the "Ohne Datum" section when empty` | Done |
+| REQ-017 | years + undated both empty → timeline.empty_state message | #779 | zeitstrahl-global-view | `frontend/src/lib/timeline/TimelineView.svelte` | `TimelineView.svelte.spec.ts#shows the empty state and no ol` | Done |
+| REQ-018 | each layer carries a non-color redundant cue (glyph aria-hidden + sr-only label) | #779 | zeitstrahl-global-view | `frontend/src/lib/timeline/eventCardConfig.ts`, `EventPill.svelte`, `WorldBand.svelte` | `TimelineView.svelte.spec.ts#redundant non-color cue label`, `EventPill.svelte.spec.ts#wraps the glyph aria-hidden`, `WorldBand.svelte.spec.ts#world glyph` | Done |
+| REQ-019 | every accent meets WCAG AA in light + dark; HISTORICAL label falls back to text-ink-2 | #779 | zeitstrahl-global-view | `frontend/src/lib/timeline/WorldBand.svelte` (text-ink-2) | manual pre-merge contrast check (both ratios recorded in PR) | Done |
+| REQ-020 | LetterCard link ≥44px touch target + visible focus-visible ring | #779 | zeitstrahl-global-view | `frontend/src/lib/timeline/LetterCard.svelte` | `LetterCard.svelte.spec.ts#has a touch target of at least 44px` | Done |
+| REQ-021 | OCR/import text rendered via `{...}` escaping; no `{@html}` in lib/timeline/ | #779 | zeitstrahl-global-view | `frontend/src/lib/timeline/*` | code review + `grep -r '@html' frontend/src/lib/timeline/` → zero; `LetterCard.svelte.spec.ts` | Done |
+| REQ-022 | non-ok load → error(status, mapped); 401 → redirect('/login'); never raw JSON | #779 | zeitstrahl-global-view | `frontend/src/routes/zeitstrahl/+page.server.ts` | `zeitstrahl/page.server.test.ts#redirects to /login on 401`, `#404`, `#500`, `#403` | Done |
+| REQ-023 | LetterCard href is exactly /documents/{documentId}, no target | #779 | zeitstrahl-global-view | `frontend/src/lib/timeline/LetterCard.svelte` | `LetterCard.svelte.spec.ts#links to exactly /documents/{documentId} with no target` | Done |
+| REQ-024 | all user-facing strings via Paraglide keys (layer/derived labels localized per locale) | #779 | zeitstrahl-global-view | `frontend/messages/{de,en,es}.json` | `messages.spec.ts#timeline layer/derived labels are localized per locale`, Paraglide compile | Done |
+| REQ-025 | personId prop declared but undefined in global view; not passed to leaf cards | #779 | zeitstrahl-global-view | `frontend/src/lib/timeline/TimelineView.svelte` | `TimelineView.svelte.spec.ts#renders all years and undated entries with personId undefined` | Done |
+| REQ-026 | month-bucket helpers in $lib/shared/utils/monthBuckets.ts; no lib/timeline → lib/document import | #779 | zeitstrahl-global-view | `frontend/src/lib/shared/utils/monthBuckets.ts` | `monthBuckets.spec.ts` (relocated) + eslint boundary + `grep lib/document` → zero | Done |
+| REQ-027 | monthHistogram returns 12 MonthBuckets for the band year via shared fillDensityGaps | #779 | zeitstrahl-global-view | `frontend/src/lib/timeline/timelineDensity.ts` | `timelineDensity.spec.ts#monthHistogram` | Done |

.specify/templates/adr.md

@@ -0,0 +1,42 @@
+<!--
+  ADR template. ADRs live in the existing archive: docs/adr/NNN-kebab-title.md.
+  Verify the next free NNN against `ls docs/adr/` on disk (parallel worktrees make
+  issue-body numbers stale). An ADR is IMMUTABLE once Status = Accepted — to change a
+  decision, write a NEW higher-numbered ADR and set this one's Status to Superseded.
+  This header mirrors the existing archive style (see docs/adr/040-*.md). Delete this comment.
+-->
+
+# ADR-NNN — <Short decision title>
+
+**Status:** Proposed <!-- Proposed | Accepted | Deprecated | Superseded by ADR-MMM -->
+**Date:** <YYYY-MM-DD>
+**Issue:** #<n> <!-- the Gitea issue / feature this decision serves -->
+
+## Context
+
+<The forces at play: what problem demands a decision now, the constraints from the
+constitution and existing ADRs, and why the status quo is insufficient. State facts, not
+the chosen answer.>
+
+## Decision
+
+<The decision, stated in active voice as something the project now does. Number sub-decisions
+(### 1, ### 2, …) if the ADR commits several related choices, matching the existing archive.>
+
+## Alternatives Considered
+
+| Option | Pros | Cons | Reason rejected |
+|---|---|---|---|
+| <chosen — name it> | <pros> | <cons> | **Chosen** |
+| <alternative A> | <pros> | <cons> | <why not> |
+| <alternative B> | <pros> | <cons> | <why not> |
+
+## Consequences
+
+<What becomes easier and what becomes harder. Include the obligations this decision places
+on future work (migrations forward-only, tests that must exist, guards that must hold), and
+any new coupling introduced.>
+
+## References
+
+- <constitution §, related ADRs, issue links, external docs>

.specify/templates/api-contract-stub.md

@@ -0,0 +1,97 @@
+# API Contract Stub
+
+This project is **REST + OpenAPI**. The backend serves the live spec via springdoc at
+`http://localhost:8080/v3/api-docs` (dev profile only), and the frontend generates its
+TypeScript client from it with `npm run generate:api` (`openapi-typescript` →
+`frontend/src/lib/generated/api.ts`). There is no GraphQL in this stack.
+
+> **The live spec is generated from the Java controllers — it is the source of truth.** A
+> hand-written stub is a *design artifact*: it pins the intended shape during spec review.
+> Issue-only: paste the stub inline into the issue's `## API / Contract Stub` section. Keep it
+> OpenAPI **3.1**, and keep `@Schema(requiredMode = REQUIRED)` on the Java side as the real
+> driver of `required`.
+
+## How to use this stub
+
+1. Fill in the skeleton below with the paths/methods/schemas your feature adds, and paste it
+   into the issue's `## API / Contract Stub` section.
+2. Every mutating path documents the `403`/`401` responses and the `cookieAuth` security
+   requirement (matching the real `@RequirePermission` gate).
+3. If you prefer a standalone, lintable file (e.g. for a large contract), commit it on the
+   **feature branch** as `<feature>.openapi.yaml` — the `sdd-gate.yml` CI job lints any
+   committed OpenAPI contract with Spectral (`npx @stoplight/spectral-cli lint`). It never
+   needs to predate the issue.
+4. After the endpoint ships, run `npm run generate:api` and diff the generated types against
+   this contract; reconcile any drift (the generated spec wins — update the contract).
+
+## OpenAPI 3.1 skeleton
+
+```yaml
+openapi: 3.1.0
+info:
+  title: Familienarchiv API — <feature name>
+  version: 0.0.1-SNAPSHOT
+  description: Design-time contract for <feature>. Source of truth is the generated /v3/api-docs.
+servers:
+  - url: http://localhost:8080
+    description: Local backend (dev profile)
+  - url: https://archiv.raddatz.cloud
+    description: Production (behind Caddy)
+components:
+  securitySchemes:
+    cookieAuth:               # Spring Session JDBC — opaque session id in the SESSION cookie
+      type: apiKey
+      in: cookie
+      name: SESSION
+  schemas:
+    ErrorResponse:            # shape produced by GlobalExceptionHandler
+      type: object
+      required: [code, message]
+      properties:
+        code:
+          type: string
+          description: Machine-readable ErrorCode (see ErrorCode.java / errors.ts).
+          example: FORBIDDEN
+        message:
+          type: string
+    # <YourResponseView>:     # always a view, never a lazy-collection entity (ADR-036)
+    #   type: object
+    #   required: [id]
+    #   properties:
+    #     id: { type: string, format: uuid }
+security:
+  - cookieAuth: []            # default: every path requires a session unless overridden to []
+paths:
+  /api/<resource>:
+    post:
+      summary: <create …>
+      operationId: <createResource>
+      security:
+        - cookieAuth: []      # plus @RequirePermission(Permission.X) on the controller
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema: { $ref: '#/components/schemas/<CreateDTO>' }
+      responses:
+        '201':
+          description: Created
+          content:
+            application/json:
+              schema: { $ref: '#/components/schemas/<YourResponseView>' }
+        '400': { description: Validation failed, content: { application/json: { schema: { $ref: '#/components/schemas/ErrorResponse' } } } }
+        '401': { description: Unauthenticated, content: { application/json: { schema: { $ref: '#/components/schemas/ErrorResponse' } } } }
+        '403': { description: Missing permission, content: { application/json: { schema: { $ref: '#/components/schemas/ErrorResponse' } } } }
+```
+
+## Validating the contract in CI
+
+The `sdd-gate.yml` `contract-validate` job lints any committed OpenAPI file changed in the PR:
+
+```bash
+npx @stoplight/spectral-cli lint <your-contract>.yaml
+```
+
+The ruleset is `.spectral.yaml` at the repo root (extends `spectral:oas`; documentation-only
+warnings relaxed for design-time stubs). Spectral auto-discovers it. It catches malformed
+specs, undefined `$ref`s, and duplicate `operationId`s; tune `.spectral.yaml` to adjust.

.specify/templates/feature-spec.md

@@ -0,0 +1,89 @@
+<!--
+  Feature Spec template — paste this into the Gitea issue body (issue-only: this IS the spec;
+  there is no committed spec.md). The .gitea/ISSUE_TEMPLATE/feature.md mirror gives the same
+  structure with the right labels. Replace every <placeholder>. Delete this comment before submitting.
+  EARS = Easy Approach to Requirements Syntax. Every requirement uses one of the five patterns
+  shown in ## Requirements and carries a unique REQ-NNN id (three-digit, scoped to THIS feature).
+  Use plain code-path references (not relative markdown links) — links don't resolve inside a Gitea issue.
+-->
+
+# <Feature title — match the Gitea issue: "As a <role> I want <capability> so <reason>">
+
+## Context & Why
+
+<Business motivation in 2–4 sentences: who needs this and why now.>
+
+Constitution principles this feature depends on (see `.specify/constitution.md`):
+- §<n> <principle name> — <why it applies>
+
+Related: <links to prior issues / ADRs>.
+
+## User Journey
+
+<Plain-prose steps the user takes to get value, from the user's perspective — per COLLABORATING.md. Anything not in this journey is out of scope.>
+
+## Requirements
+
+> One requirement per line, each with a `REQ-NNN` id and one EARS pattern. Include the
+> patterns the feature actually needs — do not force all five, but a mutating feature almost
+> always needs at least one Event-driven and one Unwanted-behavior requirement.
+
+- **REQ-001** (Ubiquitous) — The `<system component>` shall `<always-true behavior>`.
+- **REQ-002** (Event-driven) — When `<trigger / endpoint receives X>`, the `<system component>` shall `<response>`.
+- **REQ-003** (State-driven) — While `<system is in state X>`, the `<system component>` shall `<behavior>`.
+- **REQ-004** (Optional-feature) — Where `<the caller has Permission.X / a feature flag is set>`, the `<system component>` shall `<behavior>`.
+- **REQ-005** (Unwanted-behavior) — If `<undesired condition, e.g. caller is unauthenticated / input invalid>`, then the `<system component>` shall `<safe response, e.g. return 401 / ErrorCode.X>`.
+
+## Acceptance Criteria
+
+> One measurable criterion per REQ-NNN. Numbers, limits, status codes — never adjectives.
+
+- **REQ-001** — <measurable, e.g. "the response always includes a non-null `id` (UUID)">.
+- **REQ-002** — <measurable, e.g. "POST returns 201 and the persisted row within the same request">.
+- **REQ-003** — <measurable>.
+- **REQ-004** — <measurable, e.g. "a caller without Permission.X receives 403 with ErrorCode.FORBIDDEN">.
+- **REQ-005** — <measurable, e.g. "an unauthenticated request receives 401 and nothing is persisted">.
+
+## Out of Scope
+
+- <Explicit boundary statement — the nearest tempting scope creep, named and excluded.>
+- <…>
+
+## API / Contract Stub
+
+<Inline OpenAPI stub. Name the new/changed paths, methods, request/response shapes, status codes, and `@RequirePermission`. Use the `.specify/templates/api-contract-stub.md` skeleton as a writing aid.>
+
+## Data Model Changes
+
+<Entity/schema delta: new tables/columns, constraints, the next free Flyway `V<n>`, and the rollback note. Write "none" if not applicable.>
+
+## Security Considerations
+
+<STRIDE categories touched (Spoofing/Tampering/Repudiation/Information disclosure/DoS/Elevation). For AI-agent/tool features, also ASTRIDE. Include an inline STRIDE table (use `.specify/templates/threat-model.md`) if the feature has a non-trivial attack surface.>
+
+## Open Questions
+
+> Each item is a BLOCKER until resolved. Empty this list before implementation starts.
+
+- [ ] <question> — owner: <name>
+- [ ] <question> — owner: <name>
+
+## Traceability
+
+| REQ-ID | Task ID(s) | Test ID(s) | Status |
+|---|---|---|---|
+| REQ-001 | <T-1> | <test name> | Planned |
+| REQ-002 | <T-2> | <test name> | Planned |
+
+<After approval, add one committed row per REQ-NNN to `.specify/rtm.md` with this issue's number. Fill Task/Test IDs as work progresses.>
+
+## Persona Review Results
+
+| Persona | Status | Key Findings | Resolved |
+|---|---|---|---|
+| Requirements Engineer | PENDING | | |
+| Developer | PENDING | | |
+| Security | PENDING | | |
+| DevOps | PENDING | | |
+| UI/UX | PENDING | | |
+| Architect | PENDING | | |

.specify/templates/threat-model.md

@@ -0,0 +1,53 @@
+<!--
+  Threat model template — STRIDE + ASTRIDE. WRITING AID: fill this in and paste the result into
+  the issue's "## Security Considerations" section (issue-only — the threat model lives in the
+  issue body, not a committed file). Required when a feature adds a new trust boundary, handles
+  uploads, exposes a new mutating endpoint, or invokes an AI agent/tool. The Security persona
+  gates it during /review-issue. Delete this comment.
+-->
+
+# Threat Model — <Feature name>
+
+**Feature spec:** Gitea issue #<n>
+**Date:** <YYYY-MM-DD>
+**Author:** <name>
+
+## Data Flow Diagram (text)
+
+**Actors**
+- <e.g. Anonymous visitor, Authenticated reader, Authenticated transcriber, Admin, OCR sidecar>
+
+**Trust boundaries**
+- TB-1: Browser ⇄ Caddy (public internet ⇄ DMZ)
+- TB-2: Caddy ⇄ Backend (`:8080`) (DMZ ⇄ app)
+- TB-3: Backend ⇄ PostgreSQL / MinIO / sidecars (app ⇄ data plane)
+- <add feature-specific boundaries>
+
+**Data flows** (source → [boundary] → sink : data)
+- F-1: Browser → [TB-1,TB-2] → Backend : <request payload>
+- F-2: Backend → [TB-3] → MinIO : <stored object>
+- <…>
+
+## STRIDE
+
+| Threat Category | Asset / Flow | Threat Description | Mitigation | Likelihood × Impact | Status |
+|---|---|---|---|---|---|
+| **S**poofing | <asset> | <e.g. unauthenticated caller forges a request> | <session auth + @RequirePermission> | Low × High | <Open/Mitigated/Accepted> |
+| **T**ampering | <asset> | <e.g. mass-assignment of createdBy> | <server-set audit fields, no body binding> | Med × High | |
+| **R**epudiation | <asset> | <e.g. no record of who changed what> | <NOT NULL createdBy/updatedBy audit trail> | Low × Med | |
+| **I**nformation disclosure | <asset> | <e.g. entity leaks email/hash; raw 500 leaks Hibernate internals> | <view not entity; DomainException.conflict> | Med × High | |
+| **D**enial of service | <asset> | <e.g. oversized upload / unbounded list> | <size limit, batch cap, pagination> | Med × Med | |
+| **E**levation of privilege | <asset> | <e.g. reader reaches a write endpoint / IDOR> | <least-privilege Permission, ownership check> | Low × High | |
+
+## ASTRIDE (only if the feature invokes an AI agent / tool — OCR, NLP, LLM)
+
+| Threat | Asset / Flow | Threat Description | Mitigation | Likelihood × Impact | Status |
+|---|---|---|---|---|---|
+| Prompt Injection | <input to the model> | <untrusted document text steers the model> | <treat model output as untrusted; no auto-exec> | | |
+| Context Poisoning | <retrieved/shared context> | <attacker plants data that biases later runs> | <scope/provenance of context; validation> | | |
+| Unsafe Tool Invocation | <tool the agent can call> | <model triggers a privileged action> | <allow-list tools; human-in-loop on mutations> | | |
+| Reasoning Subversion | <decision the model makes> | <crafted input flips a classification/decision> | <confidence threshold; deterministic guardrail> | | |
+
+## Residual Risk
+
+<Threats marked Accepted, who accepted them, and why the residual risk is tolerable.>

.spectral.yaml

@@ -0,0 +1,15 @@
+# Spectral ruleset for OpenAPI contract linting (SDD api-contract files).
+# Spectral v6 ships no implicit ruleset — this enables the built-in OpenAPI rules.
+# Used by .gitea/workflows/sdd-gate.yml (contract-validate) and locally:
+#   npx @stoplight/spectral-cli lint <contract>.yaml
+extends: ["spectral:oas"]
+
+rules:
+  # Design-time SDD stubs are not full published API docs — relax the documentation-completeness
+  # warnings that would otherwise fire on a focused contract. The structural/correctness rules
+  # (oas3-schema, valid $refs, duplicate operationId, etc.) stay on.
+  info-contact: off
+  info-description: off
+  operation-description: off
+  operation-tag-defined: off
+  oas3-unused-component: off

CLAUDE.md

@@ -16,6 +16,10 @@ See [COLLABORATING.md](./COLLABORATING.md) for the full rules: issue tracking wo
 
 See [CODESTYLE.md](./CODESTYLE.md) for coding standards: Clean Code, DRY/KISS trade-offs (KISS wins), and SOLID principles applied to this stack.
 
+## Spec-Driven Development
+
+This project uses Spec-Driven Development. **Before implementing a feature, read [`.specify/AGENTS.md`](./.specify/AGENTS.md)** (the short, machine-readable agent rules) and obey the [`.specify/constitution.md`](./.specify/constitution.md) it references. A feature's contract is its **Gitea issue body** (EARS `REQ-NNN` requirements) — there is no committed `spec.md`; the RTM ([`.specify/rtm.md`](./.specify/rtm.md)) traces each `REQ-ID → issue # → test`. Full workflow: [SPEC_DRIVEN_DEVELOPMENT.md](./SPEC_DRIVEN_DEVELOPMENT.md); template/reference: [`.specify/features/_example/`](./.specify/features/_example/). The LLM reminders below restate constitution rules — the constitution and AGENTS.md are authoritative if they ever diverge.
+
 ---
 
 ## Stack
@@ -95,7 +99,7 @@ backend/src/main/java/org/raddatz/familienarchiv/
 │   └── relationship/    PersonRelationship sub-domain
 ├── security/            SecurityConfig, Permission, @RequirePermission, PermissionAspect
 ├── tag/                 Tag domain
-├── timeline/            Timeline (Zeitstrahl) domain — TimelineEvent, EventType, TimelineEventRepository
+├── timeline/            Timeline (Zeitstrahl) domain — TimelineEvent, TimelineEventService, TimelineEntryDTO, DerivedEventType, EventType, TimelineEventRepository; TimelineEventService.assembleDerivedEvents() returns derived life-events (Geburt/Tod/Heirat) computed on read from Person/relationship data; TimelineService assembles year-bucketed TimelineDTO (curated events + derived events + archive letters); TimelineController exposes GET /api/timeline
 └── user/                User domain — AppUser, UserGroup, UserService
 ```
 
@@ -117,6 +121,7 @@ backend/src/main/java/org/raddatz/familienarchiv/
 | `Geschichte`  | `geschichten`   | `GeschichteType` (`STORY`/`JOURNEY`); ManyToMany `persons` (Person); OneToMany `items` (JourneyItem) |
 | `JourneyItem` | `journey_items` | ManyToOne `geschichte` (Geschichte, ON DELETE CASCADE); ManyToOne `document` (Document, ON DELETE SET NULL); `position`, optional `note` |
 | `TimelineEvent` | `timeline_events` | `EventType` (`PERSONAL`/`HISTORICAL`); ManyToMany `persons` (Person) + `documents` (Document), both join FKs ON DELETE CASCADE; `DatePrecision` date block; `@Version` + NOT NULL `createdBy`/`updatedBy` audit trail |
+| `TimelineEntryDTO` | _(computed — no table)_ | Unified DTO for all timeline entries assembled by `TimelineService`; 13 fields: `kind` (`EVENT`\|`LETTER`), `precision` (raw `DatePrecision` enum), `derived` (boolean), `senderName` (non-null `String`, `""` = unknown), `receiverName` (non-null `String`, `""` = unknown), `eventDate`, `eventDateEnd`, `title`, `type` (`EventType`, null for LETTER), `eventId` (null for derived entries and letters), `documentId` (set for letters), `linkedPersonIds: List<UUID>`, `derivedType` (`DerivedEventType`, null for curated/letters); edit-affordance contract: `derived == true \|\| eventId == null` → no edit link |
 
 **`DocumentStatus` lifecycle:** `PLACEHOLDER → UPLOADED → TRANSCRIBED → REVIEWED → ARCHIVED`
 
@@ -165,7 +170,7 @@ Input DTOs live flat in the domain package. Response types are the model entitie
 
 → See [CONTRIBUTING.md §Error handling](./CONTRIBUTING.md#error-handling)
 
-**LLM reminder:** use `DomainException.notFound/forbidden/conflict/internal()` from service methods — never throw raw exceptions. When adding a new `ErrorCode`: (1) add to `ErrorCode.java`, (2) add to `ErrorCode` type in `frontend/src/lib/shared/errors.ts`, (3) add a `case` in `getErrorMessage()`, (4) add i18n keys in `messages/{de,en,es}.json`. Valid error codes include: `TOO_MANY_LOGIN_ATTEMPTS` (returned by `LoginRateLimiter` as HTTP 429 when a brute-force threshold is exceeded); `JOURNEY_NOTE_TOO_LONG`, `JOURNEY_DOCUMENT_ALREADY_ADDED`, `GESCHICHTE_TYPE_IMMUTABLE`, `GESCHICHTE_TITLE_TOO_LONG`, `GESCHICHTE_INTRO_TOO_LONG` (journey/geschichte domain constraints).
+**LLM reminder:** use `DomainException.notFound/forbidden/conflict/internal()` from service methods — never throw raw exceptions. When adding a new `ErrorCode`: (1) add to `ErrorCode.java`, (2) add to `ErrorCode` type in `frontend/src/lib/shared/errors.ts`, (3) add a `case` in `getErrorMessage()`, (4) add i18n keys in `messages/{de,en,es}.json`. Valid error codes include: `TOO_MANY_LOGIN_ATTEMPTS` (returned by `LoginRateLimiter` as HTTP 429 when a brute-force threshold is exceeded); `JOURNEY_NOTE_TOO_LONG`, `JOURNEY_DOCUMENT_ALREADY_ADDED`, `GESCHICHTE_TYPE_IMMUTABLE`, `GESCHICHTE_TITLE_TOO_LONG`, `GESCHICHTE_INTRO_TOO_LONG` (journey/geschichte domain constraints); `TIMELINE_EVENT_NOT_FOUND`, `TIMELINE_EVENT_CONFLICT`, `TIMELINE_TITLE_TOO_LONG` (timeline event CRUD), plus a generic `CONFLICT` (409 optimistic-lock backstop).
 
 ### Security / Permissions
 
@@ -202,6 +207,7 @@ frontend/src/routes/
 ├── aktivitaeten/           Unified activity feed (Chronik)
 ├── geschichten/            Stories — list, [id], [id]/edit, new
 ├── stammbaum/              Family tree (Stammbaum)
+├── zeitstrahl/             Global timeline (Zeitstrahl) — life-events + events + letters woven in time; SSR-loads GET /api/timeline, renders lib/timeline/TimelineView (Datum mode)
 ├── themen/                 Topics directory — browsable tag index
 ├── enrich/                 Enrichment workflow — [id], done
 ├── admin/                  User, group, tag, OCR, system management
@@ -273,7 +279,7 @@ Back button pattern — use the shared `<BackButton>` component from `$lib/share
 
 → See [CONTRIBUTING.md §Error handling](./CONTRIBUTING.md#error-handling)
 
-**LLM reminder:** when adding a new `ErrorCode`: (1) add to `ErrorCode.java`, (2) add to `ErrorCode` type in `frontend/src/lib/shared/errors.ts`, (3) add a `case` in `getErrorMessage()`, (4) add i18n keys in `messages/{de,en,es}.json`. Valid error codes include: `TOO_MANY_LOGIN_ATTEMPTS` (returned by `LoginRateLimiter` as HTTP 429 when a brute-force threshold is exceeded); `JOURNEY_NOTE_TOO_LONG`, `JOURNEY_DOCUMENT_ALREADY_ADDED`, `GESCHICHTE_TYPE_IMMUTABLE`, `GESCHICHTE_TITLE_TOO_LONG`, `GESCHICHTE_INTRO_TOO_LONG` (journey/geschichte domain constraints).
+**LLM reminder:** when adding a new `ErrorCode`: (1) add to `ErrorCode.java`, (2) add to `ErrorCode` type in `frontend/src/lib/shared/errors.ts`, (3) add a `case` in `getErrorMessage()`, (4) add i18n keys in `messages/{de,en,es}.json`. Valid error codes include: `TOO_MANY_LOGIN_ATTEMPTS` (returned by `LoginRateLimiter` as HTTP 429 when a brute-force threshold is exceeded); `JOURNEY_NOTE_TOO_LONG`, `JOURNEY_DOCUMENT_ALREADY_ADDED`, `GESCHICHTE_TYPE_IMMUTABLE`, `GESCHICHTE_TITLE_TOO_LONG`, `GESCHICHTE_INTRO_TOO_LONG` (journey/geschichte domain constraints); `TIMELINE_EVENT_NOT_FOUND`, `TIMELINE_EVENT_CONFLICT`, `TIMELINE_TITLE_TOO_LONG` (timeline event CRUD), plus a generic `CONFLICT` (409 optimistic-lock backstop).
 
 ---
 

COLLABORATING.md

@@ -8,6 +8,14 @@ Evaluate all suggestions on their technical merits. No sycophancy — if somethi
 
 ## Core Workflow: Research → Plan → Implement → Validate
 
+> **Spec-Driven Development.** Feature work is front-ended by an SDD spec: EARS-formatted
+> `REQ-NNN` requirements, persona spec-review checklists, and the project constitution. The
+> sequence below is unchanged — SDD formalises its *inputs* (the issue body becomes a
+> structured spec; the User Journey + E2E Scenarios below feed it). See
+> [SPEC_DRIVEN_DEVELOPMENT.md](./SPEC_DRIVEN_DEVELOPMENT.md) and
+> [`.specify/`](./.specify/) ([constitution](./.specify/constitution.md),
+> [AGENTS.md](./.specify/AGENTS.md)).
+
 Every non-trivial feature or bug fix follows this sequence:
 
 1. **Research** — Read the relevant code. Understand existing patterns before touching anything.

CONTRIBUTING.md

@@ -1,6 +1,7 @@
 # Contributing to Familienarchiv
 
 For the full collaboration rules (issue workflow, PR process, Red/Green TDD, commit conventions) see [COLLABORATING.md](./COLLABORATING.md).
+For the Spec-Driven Development workflow (EARS specs, persona review, the constitution, and `.specify/`) see [SPEC_DRIVEN_DEVELOPMENT.md](./SPEC_DRIVEN_DEVELOPMENT.md).
 For coding style see [CODESTYLE.md](./CODESTYLE.md).
 For the system architecture see [docs/ARCHITECTURE.md](./docs/ARCHITECTURE.md) (introduced in DOC-2; until that PR merges, see [docs/architecture/c4-diagrams.md](./docs/architecture/c4-diagrams.md)).
 For domain terminology see [docs/GLOSSARY.md](./docs/GLOSSARY.md).

SPEC_DRIVEN_DEVELOPMENT.md

@@ -0,0 +1,235 @@
+# Spec-Driven Development (SDD)
+
+How we turn a feature idea into merged, traceable code in this repo. SDD layers a uniform,
+machine-readable front-end onto the workflow we already run (Gitea issues → branch/PR →
+multi-persona review → red/green TDD). It does not replace any of that — see
+[ADR-042](./docs/adr/042-sdd-adoption.md) for the why.
+
+- **The rules** live in [`.specify/constitution.md`](./.specify/constitution.md) (humans) and
+  [`.specify/AGENTS.md`](./.specify/AGENTS.md) (AI agents, every invocation).
+- **The templates** live in [`.specify/templates/`](./.specify/templates/).
+- **The worked example** is [`.specify/features/_example/`](./.specify/features/_example/) — read it first.
+
+---
+
+## 0. The whole workflow at a glance
+
+```mermaid
+flowchart TD
+    idea([Feature idea]):::start --> draft
+
+    subgraph author["✍️  Author"]
+        draft[/"/draft-spec<br/>(Requirements Engineer)"/]:::skill --> issue[("Gitea issue = the SPEC<br/>EARS REQ-NNN + acceptance criteria")]:::spec
+    end
+
+    issue --> ri[/"/review-issue"/]:::skill
+    ri --> g1{"GATE 1 · spec review<br/>6 personas APPROVE?<br/>Open Questions empty?"}:::gate
+    g1 -- "FAIL / question" --> amend["Amend the issue body"]:::work --> ri
+    g1 -- "APPROVE" --> rtm["Seed RTM rows<br/>REQ-ID → issue #"]:::work
+
+    rtm --> wt["Create git worktree<br/>(pull main first)"]:::work --> impl[/"/implement"/]:::skill
+
+    subgraph build["🔁  Build · TDD per REQ-NNN"]
+        impl --> red["Red: failing test"]:::work --> green["Green: minimal code"]:::work --> sync["Refactor + sync<br/>generate:api · flip RTM → Done"]:::work --> commit["Commit · Refs #n"]:::work
+        commit -- "next REQ" --> red
+    end
+
+    build --> pr[["Open PR · Closes #n"]]:::work --> g2{"GATE 2 · CI green?<br/>ci.yml + sdd-gate.yml"}:::gate
+    g2 -- "red" --> fixci["Fix on branch"]:::work --> g2
+    g2 -- "green" --> rp[/"/review-pr"/]:::skill
+
+    rp --> g3{"GATE 3 · PR review<br/>all personas APPROVE?<br/>every REQ implemented + tested?<br/>no Do-Not-Touch violation?"}:::gate
+    g3 -- "changes requested" --> fixpr["Fix on branch"]:::work --> rp
+    g3 -- "APPROVE" --> merge([Merge → main<br/>closed issue = archived spec]):::start
+
+    rules["📐 constitution.md + AGENTS.md<br/>(bind every step)"]:::rules -.-> draft
+    rules -.-> impl
+    rules -.-> rp
+
+    classDef start fill:#1d3b53,color:#fff,stroke:#1d3b53;
+    classDef skill fill:#e8f5f0,stroke:#3aa884,color:#13352b;
+    classDef gate fill:#fff3cd,stroke:#d39e00,color:#5a4500;
+    classDef spec fill:#eef2ff,stroke:#5b6ee1,color:#1e2a5a;
+    classDef work fill:#f6f6f6,stroke:#bbb,color:#222;
+    classDef rules fill:#fdecea,stroke:#d9534f,color:#611a15;
+```
+
+> `/deliver-issue` runs **GATE 1 → discuss → build → GATE 3 (loop)** end-to-end in one go.
+
+### Prerequisites (one-time setup)
+
+Before the workflow runs cleanly, confirm these exist (most ship with this repo):
+
+- [ ] **Gitea labels** `spec-required` and `needs-review` exist (the feature template + `/draft-spec` attach them; the `labels` create-param is ignored, so they must pre-exist).
+- [ ] **Gitea MCP** server configured (`gitea`) — the skills read/write issues and PRs through it.
+- [ ] **`.spectral.yaml`** at the repo root (extends `spectral:oas`) — the CI contract check needs it.
+- [ ] **Personas present**: identities in [`.claude/personas/`](./.claude/personas/) + checklists in [`.specify/personas/`](./.specify/personas/).
+- [ ] **`.specify/constitution.md` + `AGENTS.md`** committed on `main` (so every branch inherits them).
+- [ ] **Worktrees + hooks**: new feature work goes in a `git worktree` (plus-free name); run `npm install` in `frontend/` once per worktree so the pre-commit lint hook works.
+
+### The three gates
+
+| Gate | When | Mechanism | Blocks on |
+|---|---|---|---|
+| **1 · Spec review** | after `/draft-spec`, before any code | `/review-issue` (6 persona checklists) | any persona `CHANGES REQUESTED`, or an unresolved `## Open Question` |
+| **2 · CI** | on every PR | `ci.yml` (tests · lint · semgrep) + `sdd-gate.yml` (rtm-check · contract-validate · constitution-diff) | `ci.yml` failure (hard); `sdd-gate` jobs are non-blocking during adoption — see the workflow TODO |
+| **3 · PR review** | before merge | `/review-pr` (7 personas + traceability) | any persona `Changes requested`, an unimplemented/untested `REQ-NNN`, or a constitution Do-Not-Touch violation |
+
+---
+
+## 1. The workflow in 8 steps
+
+| # | Step | Who | Artifacts created / touched |
+|---|---|---|---|
+| 1 | **Idea → Gitea issue** using the Feature template | author | Gitea issue (labels `spec-required`, `needs-review`) from `.gitea/ISSUE_TEMPLATE/feature.md` |
+| 2 | **Write the spec _in the issue body_** — Context, User Journey, EARS `REQ-NNN` requirements, measurable acceptance criteria, Out of Scope | author | the Gitea issue body **is** the spec (single source of truth — no committed `spec.md`) |
+| 3 | **Capture durable design decisions** as needed | author | a `docs/adr/` ADR for any project-wide/irreversible decision; an OpenAPI contract and a STRIDE threat model inline in the issue (use the `.specify/templates/` as the writing aid) |
+| 4 | **Persona spec review** — the six checklists gate the spec | RE, Developer, Security, DevOps, UI/UX, Architect | `/review-issue` posts each persona's checklist verdict as a Gitea comment; findings folded into the issue body |
+| 5 | **Resolve Open Questions & blocking FAILs** — spec does not proceed while any remain | author | issue body updated; `Open Questions` emptied |
+| 6 | **Seed the RTM** — one row per `REQ-NNN`, pointing at the issue | author | rows added to [`.specify/rtm.md`](./.specify/rtm.md) (`Issue: #n`, `Status: Planned`) — committed with the feature branch |
+| 7 | **Implement** in a worktree, TDD per task (failing test → green → refactor → commit); agent reads `AGENTS.md` + the **issue body** (the spec) | implementer (often an AI agent) | code + tests; `npm run generate:api` after backend changes; RTM `Status` → `Done` |
+| 8 | **PR → multi-persona PR review → merge** | reviewers | PR (`Closes #n`); the closed issue is the archived spec, the RTM rows record what shipped |
+
+The personas at step 4 review the **spec (the issue)**; the same personas at step 8 (via the
+existing `review-pr` / `deliver-issue` skills) review the **code**. Step 4 catches at spec time
+what used to surface only at step 8.
+
+**Skills that drive this:** `/draft-spec` (requirements engineer authors steps 1–2 → creates
+the issue) → `/review-issue` (step 4 gate) → `/implement` (steps 6–7) → `/review-pr` (step 8).
+`/deliver-issue` runs review → discuss → implement → review-loop end-to-end.
+
+> **Why issue-only?** The Gitea issue body is the single source of truth for a spec — there is
+> no committed per-feature `spec.md` to drift out of sync with it. The only SDD artifact that
+> lives in git per feature is the RTM row (`REQ-ID → issue # → test`). The worked example under
+> [`.specify/features/_example/`](./.specify/features/_example/) is a **template/reference**, not
+> a live feature — it shows the full artifact set in one place; real features keep the spec in
+> the issue.
+
+## 2. How a Gitea issue becomes a spec
+
+**Before (free-form issue):**
+
+> **Title:** Add profile pictures
+> Users should be able to upload a picture for their profile. Make sure it's not too big and
+> only admins can remove other people's. Show initials if there's no picture.
+
+Ambiguous: how big? which formats? what status code on rejection? what about unauthenticated
+callers? No identifiers to trace, no measurable criteria.
+
+**After (SDD-structured issue — excerpt):**
+
+> **Title:** As a user I want to upload a profile picture so other family members recognise me
+>
+> **## Requirements**
+> - **REQ-002** (Event-driven) — When an authenticated user sends `POST /api/users/me/avatar`
+>   with a valid image, the user service shall store it and return a profile view with a
+>   non-null `avatarUrl`.
+> - **REQ-008** (Unwanted-behavior) — If the uploaded file exceeds 2 MB, then the user service
+>   shall return `400 ErrorCode.AVATAR_TOO_LARGE` and store nothing.
+> - **REQ-009** (Unwanted-behavior) — If a caller without `Permission.ADMIN_USER` targets
+>   another user's avatar, then the system shall return `403 ErrorCode.FORBIDDEN`.
+>
+> **## Acceptance Criteria**
+> - **REQ-008** — a 2.1 MB PNG returns `400 AVATAR_TOO_LARGE`; bucket object count unchanged.
+
+Every behavior is now a uniquely-identified, testable, EARS-formed requirement with a
+measurable acceptance criterion. See the full version in
+[`.specify/features/_example/spec.md`](./.specify/features/_example/spec.md).
+
+## 3. How to run a persona review
+
+Each persona reads the spec, walks its checklist in `.specify/personas/<persona>.md`, and
+posts a Gitea comment with **PASS / FAIL / QUESTION** per
+item and a verdict. A `FAIL` from Security or Architect is a hard block. Concrete example:
+
+> ### Security — Spec Review
+>
+> | # | Item | Status | Note |
+> |---|---|---|---|
+> | 1 | All mutating endpoints have authn + authz `If` clauses | PASS | REQ-006 (401), REQ-009 (403) |
+> | 3 | Audit fields server-set, forbidden in body | **FAIL** | `avatarObjectKey` is bound from the request body → mass-assignment (CWE-639). Make it server-set in `UserService`. |
+> | 6 | Upload type allow-list + size | PASS | REQ-007 / REQ-008 |
+> | 9 | threat-model.md present & STRIDE-complete | **QUESTION** | Is the avatar URL public or proxied? If public S3, that's information disclosure. |
+>
+> **Verdict: CHANGES REQUESTED** — blocking FAIL: #3. Resolve #9 in the threat model.
+
+The author folds the fix into the spec (here: server-set key + authenticated proxy URL),
+empties the finding, and the persona re-reviews until `APPROVE`. This mirrors the existing
+`review-issue` skill — the persona checklists just make the spec pass/fail explicit.
+
+## 4. How the AI agent uses the spec
+
+Once the spec is `APPROVE`d and tasks are seeded, the implementer points the agent at the
+artifacts. Example prompt:
+
+> Implement Gitea issue #142 (profile picture upload). Read `.specify/AGENTS.md` and obey the
+> constitution it references. The contract is the issue body — its EARS requirements
+> REQ-001…REQ-009 and acceptance criteria. Build a red/green task list from them, write the
+> failing test for each REQ first, confirm it fails, then make it pass. After backend model
+> changes run `npm run generate:api`. Do not mark a REQ done until its test is green; flip its
+> row in `.specify/rtm.md` to Done as you go.
+
+The agent now has: the rules (`AGENTS.md` → constitution) and the exact requirements with ids
+from the issue — so its output is bounded and verifiable. (The `/implement` skill fetches the
+issue body for you via the Gitea API.)
+
+## 5. Maintenance rules
+
+- **Constitution** ([`.specify/constitution.md`](./.specify/constitution.md)) — change it only
+  when a project-wide rule genuinely changes. Bump the semantic version (MAJOR = rule
+  removed/weakened, MINOR = rule added/tightened, PATCH = wording), run the §6 Sync Impact
+  review, and let the `constitution-diff` CI job list the files to reconcile. Record the bump
+  in ADR-042's revision log (or a superseding ADR for MAJOR).
+- **AGENTS.md** — keep it under 200 lines. It cross-references the constitution; it must never
+  duplicate or contradict it.
+- **ADRs** — project-wide/irreversible decisions go in [`docs/adr/`](./docs/adr/) (next free
+  `NNN`, verify on disk). Immutable once `Accepted`; supersede, don't edit.
+- **Feature specs** — the spec is the Gitea issue body; there is no committed `spec.md`.
+  "Archiving" is just closing the issue (`Closes #n` on merge). The closed issue + the RTM
+  rows are the record of what shipped.
+- **RTM** ([`.specify/rtm.md`](./.specify/rtm.md)) — append one row per `REQ-NNN` when a spec
+  is approved, each pointing at its issue (`#n`); flip `Status` as tests go green; never delete
+  a shipped requirement's row.
+- **Personas** — update `.specify/personas/*.md` checklists when a recurring blind spot
+  appears; keep them aligned with the richer `.claude/personas/`.
+
+## 6. Quick-start cheatsheet
+
+**EARS patterns** (every requirement is one of these + a `REQ-NNN` id):
+
+| Pattern | Shape |
+|---|---|
+| Ubiquitous | `The <system> shall <behavior>.` |
+| Event-driven | `When <trigger>, the <system> shall <behavior>.` |
+| State-driven | `While <state>, the <system> shall <behavior>.` |
+| Optional-feature | `Where <feature/permission present>, the <system> shall <behavior>.` |
+| Unwanted-behavior | `If <undesired condition>, then the <system> shall <response>.` |
+
+**File locations:**
+
+| What | Where |
+|---|---|
+| Non-negotiable rules | `.specify/constitution.md` |
+| Agent rules (read every time) | `.specify/AGENTS.md` |
+| Templates (writing aids) | `.specify/templates/{feature-spec,adr,threat-model,api-contract-stub}.md` |
+| Persona checklists | `.specify/personas/*.md` |
+| In-flight feature spec | the **Gitea issue body** (not a committed file) |
+| Worked example (template/reference) | `.specify/features/_example/` |
+| Traceability matrix | `.specify/rtm.md` (`REQ-ID → issue # → test`) |
+| ADR archive | `docs/adr/NNN-*.md` |
+| Issue templates | `.gitea/ISSUE_TEMPLATE/{feature,bug}.md` |
+| CI gate | `.gitea/workflows/sdd-gate.yml` |
+
+**Before you mark a feature done:** every `REQ-NNN` has a green test, the RTM Status is
+`Done`, all six personas APPROVE, `npm run lint` and the targeted tests pass, and
+`npm run generate:api` has been run if the backend model changed.
+
+**Commands:**
+
+```bash
+# validate an OpenAPI contract locally (if you drafted one — same as CI)
+npx @stoplight/spectral-cli lint <your-contract>.yaml
+
+# regenerate the TS client after a backend model/endpoint change
+cd frontend && npm run generate:api   # backend must run with --spring.profiles.active=dev
+```

backend/src/main/java/org/raddatz/familienarchiv/document/DocumentRepository.java

@@ -56,6 +56,11 @@ public interface DocumentRepository extends JpaRepository<Document, UUID>, JpaSp
     // Prüft effizient, ob ein Dateiname schon existiert (gibt true/false zurück)
     boolean existsByOriginalFilename(String originalFilename);
 
+    // Bulk-fetch for global timeline path — single query with sender+receivers eager-loaded.
+    @EntityGraph("Document.list")
+    @Query("SELECT d FROM Document d")
+    List<Document> findAllForTimeline();
+
     // lazy – @BatchSize(50) fallback active; see ADR-022
     @EntityGraph("Document.full")
     List<Document> findBySenderId(UUID senderId);

backend/src/main/java/org/raddatz/familienarchiv/document/DocumentService.java

@@ -1051,6 +1051,10 @@ public class DocumentService {
         return documentRepository.findDocumentsWithoutVersions();
     }
 
+    public List<Document> getAllForTimeline() {
+        return documentRepository.findAllForTimeline();
+    }
+
     public List<Document> getDocumentsBySender(UUID senderId) {
         return documentRepository.findBySenderId(senderId);
     }

backend/src/main/java/org/raddatz/familienarchiv/exception/ErrorCode.java

@@ -155,6 +155,14 @@ public enum ErrorCode {
     /** The merge target is a descendant of the source tag. 400 */
     TAG_MERGE_INVALID_TARGET,
 
+    // --- Timeline (Zeitstrahl) ---
+    /** A timeline event with the given ID does not exist. 404 */
+    TIMELINE_EVENT_NOT_FOUND,
+    /** Optimistic-locking conflict — the timeline event was modified by another curator. 409 */
+    TIMELINE_EVENT_CONFLICT,
+    /** A timeline event title exceeds the maximum length (255 characters — the DB column bound). 400 */
+    TIMELINE_TITLE_TOO_LONG,
+
     // --- Generic ---
     /** Request validation failed (missing or malformed fields). 400 */
     VALIDATION_ERROR,
@@ -162,6 +170,8 @@ public enum ErrorCode {
     BATCH_TOO_LARGE,
     /** Bulk edit request exceeds the per-request document ID cap. 400 */
     BULK_EDIT_TOO_MANY_IDS,
+    /** A concurrent modification was detected (generic optimistic-lock backstop). 409 */
+    CONFLICT,
     /** An unexpected server-side error occurred. 500 */
     INTERNAL_ERROR,
 }

backend/src/main/java/org/raddatz/familienarchiv/exception/GlobalExceptionHandler.java

@@ -104,6 +104,30 @@ public class GlobalExceptionHandler {
         return "unknown";
     }
 
+    /**
+     * Generic backstop for optimistic-locking conflicts that escape a service-level catch. A
+     * conflict is a 409, not a system fault — so, like {@link #handleDataIntegrityViolation}, it
+     * must NOT fire Sentry and must NOT leak Hibernate internals (CWE-209): the response carries
+     * only the generic {@link ErrorCode#CONFLICT} code and a generic message — no entity id, no
+     * version, no persistent-class name.
+     *
+     * <p>Deliberately code-GENERIC: do NOT {@code switch} on {@code getPersistentClassName()} to map
+     * back to a per-entity code. Unlike {@link #handleDataIntegrityViolation}, which branches on
+     * stable schema constraint NAMES, persistent-class names are not a contract. The precise,
+     * code-carrying path is the service catch (e.g. {@code TIMELINE_EVENT_CONFLICT}); this is only
+     * the net that keeps any current or future write path from regressing to a 500.
+     */
+    @ExceptionHandler(org.springframework.orm.ObjectOptimisticLockingFailureException.class)
+    public ResponseEntity<ErrorResponse> handleOptimisticLock(
+            org.springframework.orm.ObjectOptimisticLockingFailureException ex) {
+        // Log the persistent-class name ONLY (schema metadata, safe for Loki). Never `ex` /
+        // ex.getMessage(): those embed the entity id + version (CWE-209). No Sentry: it's a 409.
+        log.warn("Rejected a write that lost an optimistic-lock race on: {}", ex.getPersistentClassName());
+        return ResponseEntity.status(409)
+                .body(new ErrorResponse(ErrorCode.CONFLICT,
+                        "The resource was modified concurrently. Please reload and try again."));
+    }
+
     @ExceptionHandler(Exception.class)
     public ResponseEntity<ErrorResponse> handleGeneric(Exception ex) {
         Sentry.captureException(ex);

backend/src/main/java/org/raddatz/familienarchiv/person/PersonRepository.java

@@ -242,4 +242,7 @@ public interface PersonRepository extends JpaRepository<Person, UUID> {
               )
             """, nativeQuery = true)
     void insertMissingReceiverReference(@Param("source") UUID source, @Param("target") UUID target);
+
+    // Boxed Integer — matches the nullable person.generation column (primitive int would reject null rows).
+    List<Person> findByGeneration(Integer generation);
 }

backend/src/main/java/org/raddatz/familienarchiv/person/PersonService.java

@@ -210,6 +210,10 @@ public class PersonService {
         return personRepository.findByFamilyMemberTrueOrderByLastNameAscFirstNameAsc();
     }
 
+    public List<Person> getPersonsByGeneration(Integer generation) {
+        return personRepository.findByGeneration(generation);
+    }
+
     @Transactional
     public Person setFamilyMember(UUID personId, boolean familyMember) {
         Person person = getById(personId);

backend/src/main/java/org/raddatz/familienarchiv/person/relationship/RelationshipService.java

@@ -86,6 +86,15 @@ public class RelationshipService {
         return new NetworkDTO(nodes, edges);
     }
 
+    /**
+     * Returns all {@code SPOUSE_OF} edges with both person sides JOIN FETCHed.
+     * Used by {@code TimelineService.assembleDerivedEvents()} to build Heirat events
+     * without per-edge N+1 queries.
+     */
+    public List<PersonRelationship> findAllSpouseEdges() {
+        return relationshipRepository.findAllByRelationTypeIn(List.of(RelationType.SPOUSE_OF));
+    }
+
     @Transactional
     public RelationshipDTO addRelationship(UUID personId, CreateRelationshipRequest dto) {
         if (personId.equals(dto.relatedPersonId())) {

backend/src/main/java/org/raddatz/familienarchiv/timeline/DerivedEventType.java

@@ -0,0 +1,8 @@
+package org.raddatz.familienarchiv.timeline;
+
+/** Discriminator for derived life-events assembled from Person / PersonRelationship data. */
+public enum DerivedEventType {
+    BIRTH,
+    DEATH,
+    MARRIAGE
+}

backend/src/main/java/org/raddatz/familienarchiv/timeline/Kind.java

@@ -0,0 +1,7 @@
+package org.raddatz.familienarchiv.timeline;
+
+/** Discriminates curated/derived events from archive letters in {@link TimelineEntryDTO}. */
+public enum Kind {
+    EVENT,
+    LETTER
+}

backend/src/main/java/org/raddatz/familienarchiv/timeline/TimelineController.java

@@ -0,0 +1,33 @@
+package org.raddatz.familienarchiv.timeline;
+
+import jakarta.validation.constraints.Min;
+import lombok.RequiredArgsConstructor;
+import org.raddatz.familienarchiv.security.Permission;
+import org.raddatz.familienarchiv.security.RequirePermission;
+import org.springframework.validation.annotation.Validated;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.UUID;
+
+@RestController
+@RequestMapping("/api/timeline")
+@Validated
+@RequiredArgsConstructor
+public class TimelineController {
+
+    private final TimelineService timelineService;
+
+    @GetMapping
+    @RequirePermission(Permission.READ_ALL)
+    public TimelineDTO getTimeline(
+            @RequestParam(required = false) UUID personId,
+            @RequestParam(required = false) @Min(0) Integer generation,
+            @RequestParam(required = false) EventType type,
+            @RequestParam(required = false) Integer fromYear,
+            @RequestParam(required = false) Integer toYear) {
+        return timelineService.assemble(new TimelineFilter(personId, generation, type, fromYear, toYear));
+    }
+}

backend/src/main/java/org/raddatz/familienarchiv/timeline/TimelineDTO.java

@@ -0,0 +1,15 @@
+package org.raddatz.familienarchiv.timeline;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+import java.util.List;
+
+/**
+ * Assembled timeline response. Year bands are sorted ascending (oldest first).
+ * Undated entries have no usable date or {@code UNKNOWN} precision.
+ */
+public record TimelineDTO(
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) List<TimelineYearDTO> years,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) List<TimelineEntryDTO> undated
+) {
+}

backend/src/main/java/org/raddatz/familienarchiv/timeline/TimelineEntryDTO.java

@@ -0,0 +1,42 @@
+package org.raddatz.familienarchiv.timeline;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+import org.raddatz.familienarchiv.document.DatePrecision;
+
+import java.time.LocalDate;
+import java.util.List;
+import java.util.UUID;
+
+/**
+ * Unified DTO for timeline entries — covers curated {@link TimelineEvent} rows, derived
+ * life-events ({@link DerivedEventType}), and archive letters (Documents).
+ *
+ * <p><b>Edit-affordance contract (for issue #7):</b> {@code derived == true || eventId == null}
+ * means no edit link should be rendered by the frontend.
+ *
+ * <p><b>Letter display fields:</b> {@code senderName} — {@code ""} means unknown/unlinked
+ * correspondent; frontend renders {@code 'Unbekannt'} fallback. Only populated for
+ * {@link Kind#LETTER} entries.
+ *
+ * <p><b>Type field:</b> {@code null} for {@link Kind#LETTER} entries; frontend must not render
+ * an event-type badge for letters.
+ *
+ * <p>Callers of {@code TimelineEventService.assembleDerivedEvents()} must independently enforce
+ * {@code READ_ALL} authorization before invoking that method (see ADR-043).
+ */
+public record TimelineEntryDTO(
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) Kind kind,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) DatePrecision precision,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) boolean derived,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) String senderName,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) String receiverName,
+        LocalDate eventDate,
+        LocalDate eventDateEnd,
+        String title,
+        EventType type,
+        UUID eventId,
+        UUID documentId,
+        List<UUID> linkedPersonIds,
+        DerivedEventType derivedType
+) {
+}

backend/src/main/java/org/raddatz/familienarchiv/timeline/TimelineEventController.java

@@ -0,0 +1,71 @@
+package org.raddatz.familienarchiv.timeline;
+
+import jakarta.validation.Valid;
+
+import lombok.RequiredArgsConstructor;
+
+import org.raddatz.familienarchiv.security.Permission;
+import org.raddatz.familienarchiv.security.RequirePermission;
+import org.raddatz.familienarchiv.security.SecurityUtils;
+import org.raddatz.familienarchiv.user.UserService;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.security.core.Authentication;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.ResponseStatus;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.UUID;
+
+@RestController
+@RequestMapping("/api/timeline/events")
+@RequiredArgsConstructor
+public class TimelineEventController {
+
+    private final TimelineEventService timelineEventService;
+    private final UserService userService;
+
+    /**
+     * No {@code @RequirePermission} on GET by design: the global {@code anyRequest().authenticated()}
+     * rule is the READ_ALL baseline, consistent with {@code DocumentController.getDocument}. Do not
+     * "fix" the missing annotation.
+     */
+    @GetMapping("/{id}")
+    public TimelineEventView getEvent(@PathVariable UUID id) {
+        return timelineEventService.getEvent(id);
+    }
+
+    @PostMapping
+    @ResponseStatus(HttpStatus.CREATED)
+    @RequirePermission(Permission.WRITE_ALL)
+    public TimelineEventView create(@Valid @RequestBody TimelineEventRequest request, Authentication authentication) {
+        return timelineEventService.create(request, requireUserId(authentication));
+    }
+
+    @PutMapping("/{id}")
+    @RequirePermission(Permission.WRITE_ALL)
+    public TimelineEventView update(
+            @PathVariable UUID id,
+            @Valid @RequestBody TimelineEventRequest request,
+            Authentication authentication) {
+        return timelineEventService.update(id, request, requireUserId(authentication));
+    }
+
+    @DeleteMapping("/{id}")
+    @RequirePermission(Permission.WRITE_ALL)
+    public ResponseEntity<Void> delete(@PathVariable UUID id) {
+        timelineEventService.delete(id);
+        return ResponseEntity.noContent().build();
+    }
+
+    private UUID requireUserId(Authentication authentication) {
+        return SecurityUtils.requireUserId(authentication, userService);
+    }
+}

backend/src/main/java/org/raddatz/familienarchiv/timeline/TimelineEventRequest.java

@@ -0,0 +1,40 @@
+package org.raddatz.familienarchiv.timeline;
+
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Size;
+
+import org.raddatz.familienarchiv.document.DatePrecision;
+
+import java.time.LocalDate;
+import java.util.List;
+import java.util.UUID;
+
+/**
+ * Flat input DTO for creating/updating a {@link TimelineEvent}. Bean Validation fires at the
+ * controller boundary (via {@code @Valid}) and produces a 400 {@code VALIDATION_ERROR} for the
+ * presence/size constraints below; cross-field rules (the RANGE invariant), date normalization,
+ * id dedupe, and the title-length structured-error guard live in {@code TimelineEventService}.
+ *
+ * <p><strong>{@code createdBy}/{@code updatedBy} are intentionally absent.</strong> Authorship is
+ * server-populated from the session principal only — accepting it from the body would be an
+ * authorship-forgery / mass-assignment vector (CWE-639; see ADR-040 §7).
+ *
+ * @param version optional optimistic-lock concurrency token (the {@code @Version} the client last
+ *                saw), applied on <em>update</em> only. This is a concurrency token, <strong>not</strong>
+ *                an authorship field, so it is deliberately exempt from the §7 server-only audit rule.
+ *                Null on update means "no concurrency check" (last-write-wins). No range validation —
+ *                a stale/negative value is simply a mismatch the lock rejects at flush; the lock, not
+ *                a validator, is the control.
+ */
+public record TimelineEventRequest(
+        @NotBlank @Size(max = 255) String title,
+        @NotNull EventType type,
+        @NotNull LocalDate eventDate,
+        DatePrecision precision,
+        LocalDate eventDateEnd,
+        @Size(max = 5000) String description,
+        Long version,
+        @Size(max = 50) List<UUID> personIds,
+        @Size(max = 50) List<UUID> documentIds
+) {}

backend/src/main/java/org/raddatz/familienarchiv/timeline/TimelineEventService.java

@@ -0,0 +1,327 @@
+package org.raddatz.familienarchiv.timeline;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+import org.raddatz.familienarchiv.document.DatePrecision;
+import org.raddatz.familienarchiv.document.Document;
+import org.raddatz.familienarchiv.document.DocumentService;
+import org.raddatz.familienarchiv.exception.DomainException;
+import org.raddatz.familienarchiv.exception.ErrorCode;
+import org.raddatz.familienarchiv.person.Person;
+import org.raddatz.familienarchiv.person.PersonService;
+import org.raddatz.familienarchiv.person.relationship.PersonRelationship;
+import org.raddatz.familienarchiv.person.relationship.RelationshipService;
+import org.raddatz.familienarchiv.timeline.TimelineEventView.DocumentRef;
+import org.raddatz.familienarchiv.timeline.TimelineEventView.PersonView;
+
+import org.springframework.orm.ObjectOptimisticLockingFailureException;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.time.LocalDate;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.UUID;
+
+/**
+ * Curator CRUD for {@link TimelineEvent}. Persons and documents are resolved through their own
+ * services (never their repositories). All four body-returning operations return a
+ * {@link TimelineEventView} assembled in-transaction — the entity is never serialized (ADR-040 §2).
+ */
+@Service
+@RequiredArgsConstructor
+@Slf4j
+public class TimelineEventService {
+
+    private static final int MAX_TITLE_LENGTH = 255;
+
+    private final TimelineEventRepository events;
+    private final PersonService personService;
+    private final DocumentService documentService;
+    private final RelationshipService relationshipService;
+
+    @Transactional
+    public TimelineEventView create(TimelineEventRequest request, UUID actorId) {
+        DatePrecision precision = effectivePrecision(request);
+        validateRangeInvariant(request, precision);
+        validateTitleLength(request);
+
+        TimelineEvent event = TimelineEvent.builder()
+                .title(request.title())
+                .type(request.type())
+                .eventDate(normalizeEventDate(request.eventDate(), precision))
+                .precision(precision)
+                .eventDateEnd(request.eventDateEnd())
+                .description(request.description())
+                .persons(resolvePersons(request.personIds()))
+                .documents(resolveDocuments(request.documentIds()))
+                .createdBy(actorId)
+                .updatedBy(actorId)
+                .build();
+
+        return toView(events.saveAndFlush(event));
+    }
+
+    @Transactional
+    public TimelineEventView update(UUID id, TimelineEventRequest request, UUID actorId) {
+        TimelineEvent event = events.findById(id)
+                .orElseThrow(() -> DomainException.notFound(ErrorCode.TIMELINE_EVENT_NOT_FOUND,
+                        "Timeline event not found: " + id));
+        requireVersionMatch(request, event);
+        DatePrecision precision = effectivePrecision(request);
+        validateRangeInvariant(request, precision);
+        validateTitleLength(request);
+        applyUpdate(event, request, precision, actorId);
+
+        // saveAndFlush (not save) so the versioned UPDATE …WHERE version=? fires HERE, inside the
+        // try — a bare save() flushes at commit, after this method returns, so the exception would
+        // escape the catch and surface as a 500. Catch the Spring-translated type, not JPA's.
+        try {
+            return toView(events.saveAndFlush(event));
+        } catch (ObjectOptimisticLockingFailureException ex) {
+            throw DomainException.conflict(ErrorCode.TIMELINE_EVENT_CONFLICT,
+                    "Timeline event was modified concurrently: " + id);
+        }
+    }
+
+    @Transactional
+    public void delete(UUID id) {
+        TimelineEvent event = events.findById(id)
+                .orElseThrow(() -> DomainException.notFound(ErrorCode.TIMELINE_EVENT_NOT_FOUND,
+                        "Timeline event not found: " + id));
+        events.delete(event);
+    }
+
+    /**
+     * View-assembly read. {@code @Transactional(readOnly = true)} is load-bearing, not optional:
+     * the LAZY {@code persons}/{@code documents} collections are traversed during {@link #toView}
+     * assembly, and under {@code open-in-view: false} a closed session there is a
+     * {@code LazyInitializationException} (ADR-022 / {@code getDocumentDetail} precedent).
+     */
+    @Transactional(readOnly = true)
+    public TimelineEventView getEvent(UUID id) {
+        TimelineEvent event = events.findById(id)
+                .orElseThrow(() -> DomainException.notFound(ErrorCode.TIMELINE_EVENT_NOT_FOUND,
+                        "Timeline event not found: " + id));
+        return toView(event);
+    }
+
+    // --- update mechanics: mutate the managed entity, never reassign collections ---
+
+    private void applyUpdate(TimelineEvent event, TimelineEventRequest request, DatePrecision precision, UUID actorId) {
+        event.setTitle(request.title());
+        event.setType(request.type());
+        event.setEventDate(normalizeEventDate(request.eventDate(), precision));
+        event.setPrecision(precision);
+        event.setEventDateEnd(request.eventDateEnd());
+        event.setDescription(request.description());
+        replaceLinks(event, request);
+        event.setUpdatedBy(actorId); // preserve createdBy — only the editor changes
+    }
+
+    /**
+     * Compares the client's concurrency token against the freshly-loaded version (the Q1
+     * "last-seen version" token). A mismatch means the client edited stale data → 409.
+     *
+     * <p>This explicit compare is the control — NOT {@code event.setVersion(clientVersion)} before
+     * flush. Setting {@code @Version} on a <em>managed</em> entity is silently ignored by Hibernate
+     * for the optimistic check: it uses its own loaded-version snapshot for the
+     * {@code UPDATE … WHERE version=?} clause, so a stale token never reaches the DB. The native
+     * {@code @Version} increment still happens on every save, and the {@code saveAndFlush}+catch
+     * below remains the backstop for two transactions flushing concurrently; this guard is what
+     * catches the human-timescale "B submitted a form based on a version A already superseded" case.
+     * A null token means no check (last-write-wins) until #9 always sends it.
+     */
+    private void requireVersionMatch(TimelineEventRequest request, TimelineEvent event) {
+        if (request.version() != null && !request.version().equals(event.getVersion())) {
+            throw DomainException.conflict(ErrorCode.TIMELINE_EVENT_CONFLICT,
+                    "Timeline event was modified concurrently: " + event.getId());
+        }
+    }
+
+    /**
+     * Replaces (set semantics) the link collections. Mutates the existing managed collections —
+     * Hibernate does not track a reassigned reference, and a fresh {@code Set} risks orphan join
+     * rows against the {@code ON DELETE CASCADE} join tables. A null or empty list clears all links.
+     */
+    private void replaceLinks(TimelineEvent event, TimelineEventRequest request) {
+        event.getPersons().clear();
+        event.getPersons().addAll(resolvePersons(request.personIds()));
+        event.getDocuments().clear();
+        event.getDocuments().addAll(resolveDocuments(request.documentIds()));
+    }
+
+    // --- validation / normalization ---
+
+    /**
+     * Mirrors the DB biconditional CHECK chk_timeline_event_range — both presence directions — and
+     * additionally enforces date ordering, which the DB CHECK does NOT: {@code eventDateEnd} may
+     * equal but never precede {@code eventDate}. Without this guard a reversed range (end before
+     * start) persists silently and renders as a negative span. Equal dates are a valid one-day
+     * closed range.
+     */
+    private void validateRangeInvariant(TimelineEventRequest request, DatePrecision precision) {
+        boolean isRange = precision == DatePrecision.RANGE;
+        if (request.eventDateEnd() != null && !isRange) {
+            throw DomainException.badRequest(ErrorCode.INVALID_DATE_RANGE,
+                    "eventDateEnd is only valid when precision is RANGE");
+        }
+        if (isRange && request.eventDateEnd() == null) {
+            throw DomainException.badRequest(ErrorCode.INVALID_DATE_RANGE,
+                    "A RANGE event requires a non-null eventDateEnd");
+        }
+        if (isRange && request.eventDateEnd().isBefore(request.eventDate())) {
+            throw DomainException.badRequest(ErrorCode.INVALID_DATE_RANGE,
+                    "eventDateEnd must not precede eventDate");
+        }
+    }
+
+    /**
+     * Load-bearing only for non-HTTP callers: the DTO {@code @Size(max = 255)} already covers HTTP
+     * callers, but a non-HTTP caller could otherwise push an over-long title to the VARCHAR(255)
+     * column and get a raw {@code DataIntegrityViolationException} → 500. Do not delete as
+     * "duplicate validation".
+     */
+    private void validateTitleLength(TimelineEventRequest request) {
+        if (request.title() != null && request.title().length() > MAX_TITLE_LENGTH) {
+            throw DomainException.badRequest(ErrorCode.TIMELINE_TITLE_TOO_LONG,
+                    "Title exceeds maximum length of " + MAX_TITLE_LENGTH + " characters");
+        }
+    }
+
+    private DatePrecision effectivePrecision(TimelineEventRequest request) {
+        return request.precision() != null ? request.precision() : DatePrecision.YEAR;
+    }
+
+    private LocalDate normalizeEventDate(LocalDate eventDate, DatePrecision precision) {
+        return precision == DatePrecision.YEAR ? LocalDate.of(eventDate.getYear(), 1, 1) : eventDate;
+    }
+
+    // --- link resolution (fail-closed, dedupe-first) ---
+
+    private Set<Person> resolvePersons(List<UUID> ids) {
+        if (ids == null || ids.isEmpty()) {
+            return new HashSet<>();
+        }
+        // Dedupe FIRST: [idA, idA] is one link, not a 404. findAllById dedupes too, so compare the
+        // resolved size against the DISTINCT input count — a raw ids.size() compare reports a spurious
+        // mismatch.
+        Set<UUID> distinct = new LinkedHashSet<>(ids);
+        List<Person> resolved = personService.getAllById(new ArrayList<>(distinct));
+        if (resolved.size() != distinct.size()) {
+            throw DomainException.notFound(ErrorCode.PERSON_NOT_FOUND, "One or more person IDs not found");
+        }
+        return new HashSet<>(resolved);
+    }
+
+    private Set<Document> resolveDocuments(List<UUID> ids) {
+        if (ids == null || ids.isEmpty()) {
+            return new HashSet<>();
+        }
+        // Per-id loop on purpose: DocumentService has no batch fetch, and per-id gives free
+        // DOCUMENT_NOT_FOUND 404s. getDocumentById is @Transactional(readOnly = true) and joins this
+        // write tx via Spring's default REQUIRED propagation — do NOT "optimize" into a phantom batch.
+        Set<Document> resolved = new HashSet<>();
+        for (UUID documentId : new LinkedHashSet<>(ids)) {
+            resolved.add(documentService.getDocumentById(documentId));
+        }
+        return resolved;
+    }
+
+    // --- derived event assembly ---
+
+    /**
+     * Assembles derived life-events (Geburt/Tod/Heirat) from curated Person and
+     * PersonRelationship data. Computed on read, never persisted.
+     *
+     * <p>Derived events are computed, never persisted, and cannot be mutated via the events API
+     * (enforced in #5). Ids produced by this method are structurally non-UUID
+     * ({@code birth:*}, {@code death:*}, {@code marriage:*}) and MUST be rejected by any
+     * write endpoint — enforced and tested in #5. Callers outside the #5 endpoint must
+     * independently enforce {@code READ_ALL} authorization before invoking this method
+     * (see ADR-043).
+     */
+    @Transactional(readOnly = true)
+    public List<TimelineEntryDTO> assembleDerivedEvents() {
+        List<Person> persons = personService.findAllFamilyMembers();
+        List<PersonRelationship> spouseEdges = relationshipService.findAllSpouseEdges();
+
+        List<TimelineEntryDTO> result = new ArrayList<>();
+        result.addAll(buildBirthEvents(persons));
+        result.addAll(buildDeathEvents(persons));
+        result.addAll(buildMarriageEvents(spouseEdges));
+
+        log.debug("Assembled {} derived events for {} persons", result.size(), persons.size());
+        return result;
+    }
+
+    private List<TimelineEntryDTO> buildBirthEvents(List<Person> persons) {
+        return persons.stream()
+                .filter(p -> p.getBirthDate() != null)
+                .map(p -> new TimelineEntryDTO(
+                        Kind.EVENT, p.getBirthDatePrecision(), true, "", "",
+                        p.getBirthDate(), null,
+                        p.getDisplayName(), EventType.PERSONAL,
+                        null, null, List.of(p.getId()), DerivedEventType.BIRTH))
+                .toList();
+    }
+
+    private List<TimelineEntryDTO> buildDeathEvents(List<Person> persons) {
+        return persons.stream()
+                .filter(p -> p.getDeathDate() != null)
+                .map(p -> new TimelineEntryDTO(
+                        Kind.EVENT, p.getDeathDatePrecision(), true, "", "",
+                        p.getDeathDate(), null,
+                        p.getDisplayName(), EventType.PERSONAL,
+                        null, null, List.of(p.getId()), DerivedEventType.DEATH))
+                .toList();
+    }
+
+    private List<TimelineEntryDTO> buildMarriageEvents(List<PersonRelationship> spouseEdges) {
+        // DB constraint unique_spouse_pair (V55) is the authoritative enforcement;
+        // in-memory dedup on relationship row id is a defensive assertion.
+        Set<UUID> seen = new HashSet<>();
+        List<TimelineEntryDTO> result = new ArrayList<>();
+        for (PersonRelationship r : spouseEdges) {
+            if (seen.add(r.getId())) {
+                // JOIN FETCH in findAllSpouseEdges() guarantees person/relatedPerson are loaded
+                LocalDate eventDate = r.getFromYear() != null
+                        ? LocalDate.of(r.getFromYear(), 1, 1)
+                        : null;
+                DatePrecision precision = r.getFromYear() != null
+                        ? DatePrecision.YEAR
+                        : DatePrecision.UNKNOWN;
+                String title = r.getPerson().getDisplayName()
+                        + " & " + r.getRelatedPerson().getDisplayName();
+                result.add(new TimelineEntryDTO(
+                        Kind.EVENT, precision, true, "", "",
+                        eventDate, null,
+                        title, EventType.PERSONAL,
+                        null, null,
+                        List.of(r.getPerson().getId(), r.getRelatedPerson().getId()),
+                        DerivedEventType.MARRIAGE));
+            }
+        }
+        return result;
+    }
+
+    // --- view assembly (explicit allow-list; never the raw entity) ---
+
+    private TimelineEventView toView(TimelineEvent event) {
+        List<PersonView> persons = event.getPersons().stream()
+                .map(p -> new PersonView(p.getId(), p.getFirstName(), p.getLastName()))
+                .toList();
+        List<DocumentRef> documents = event.getDocuments().stream()
+                .map(d -> new DocumentRef(d.getId(), d.getTitle(), d.getDocumentDate()))
+                .toList();
+        return new TimelineEventView(
+                event.getId(), event.getTitle(), event.getType(), event.getEventDate(),
+                event.getPrecision(), event.getEventDateEnd(), event.getDescription(), event.getVersion(),
+                event.getCreatedBy(), event.getCreatedAt(), event.getUpdatedBy(), event.getUpdatedAt(),
+                persons, documents);
+    }
+}

backend/src/main/java/org/raddatz/familienarchiv/timeline/TimelineEventView.java

@@ -0,0 +1,59 @@
+package org.raddatz.familienarchiv.timeline;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+import org.raddatz.familienarchiv.document.DatePrecision;
+
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.util.List;
+import java.util.UUID;
+
+/**
+ * Response view for the timeline event endpoints — returned by GET, POST, and PUT alike.
+ * Assembled inside the service transaction (after {@code saveAndFlush} on the write paths, so
+ * {@code version} is non-null) from the managed entity's already-loaded collections. The raw
+ * {@link TimelineEvent} is never serialized: its LAZY {@code persons}/{@code documents}
+ * collections under {@code open-in-view: false} would otherwise 500 (ADR-036/ADR-040 §2), and
+ * splatting the entities would leak curator-internal fields ({@code Person.notes},
+ * {@code provisional}, transcription data) to every READ_ALL reader. The explicit field
+ * allow-list below is that guarantee.
+ */
+public record TimelineEventView(
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) UUID id,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) String title,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) EventType type,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) LocalDate eventDate,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) DatePrecision precision,
+        LocalDate eventDateEnd,
+        String description,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) Long version,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) UUID createdBy,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) LocalDateTime createdAt,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) UUID updatedBy,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) LocalDateTime updatedAt,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) List<PersonView> persons,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) List<DocumentRef> documents
+) {
+    /** Summarised person — exposes only id, firstName, and lastName. Mirrors GeschichteView.PersonView. */
+    public record PersonView(
+            @Schema(requiredMode = Schema.RequiredMode.REQUIRED) UUID id,
+            String firstName,
+            String lastName
+    ) {}
+
+    /**
+     * Summarised linked document — id, title, and the eager {@code documentDate} only (no lazy
+     * sender/receiver hop, no person-name leak through the document side).
+     *
+     * <p>timeline-local by design; do not promote to {@code document/} — see #775 R7. Reusing
+     * {@code geschichte.journeyitem.DocumentSummary} would force a cross-domain import of a
+     * package-private mapper plus duplicated name-assembly logic; a 3-field local record is the
+     * lower-coupling choice.
+     */
+    public record DocumentRef(
+            @Schema(requiredMode = Schema.RequiredMode.REQUIRED) UUID id,
+            @Schema(requiredMode = Schema.RequiredMode.REQUIRED) String title,
+            LocalDate documentDate
+    ) {}
+}

backend/src/main/java/org/raddatz/familienarchiv/timeline/TimelineFilter.java

@@ -0,0 +1,16 @@
+package org.raddatz.familienarchiv.timeline;
+
+import java.util.UUID;
+
+/**
+ * Immutable filter bag for {@link TimelineService#assemble(TimelineFilter)}.
+ * All fields are nullable — null means "no constraint on this dimension".
+ */
+public record TimelineFilter(
+        UUID personId,
+        Integer generation,
+        EventType type,
+        Integer fromYear,
+        Integer toYear
+) {
+}

backend/src/main/java/org/raddatz/familienarchiv/timeline/TimelineService.java

@@ -0,0 +1,268 @@
+package org.raddatz.familienarchiv.timeline;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+import org.raddatz.familienarchiv.document.DatePrecision;
+import org.raddatz.familienarchiv.document.Document;
+import org.raddatz.familienarchiv.document.DocumentService;
+import org.raddatz.familienarchiv.exception.DomainException;
+import org.raddatz.familienarchiv.exception.ErrorCode;
+import org.raddatz.familienarchiv.person.Person;
+import org.raddatz.familienarchiv.person.PersonService;
+
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.TreeMap;
+import java.util.UUID;
+import java.util.stream.Collectors;
+
+/**
+ * Assembles the family timeline from three sources — curated {@link TimelineEvent} rows,
+ * derived person life-events, and archive letters — into a year-bucketed {@link TimelineDTO}.
+ *
+ * <p>Cross-domain data is reached exclusively through domain services (PersonService,
+ * DocumentService). The only repository injected directly is {@link TimelineEventRepository}
+ * (same domain — constitution §1.3).
+ */
+@Service
+@RequiredArgsConstructor
+@Slf4j
+public class TimelineService {
+
+    /** Primary: precision rank descending (DAY first). Secondary: date ascending. Tertiary: title. Final: id. */
+    static final Comparator<TimelineEntryDTO> WITHIN_BAND_ORDER =
+            Comparator.comparingInt((TimelineEntryDTO e) -> precisionRank(e.precision())).reversed()
+                    .thenComparing(e -> e.eventDate() != null ? e.eventDate() : java.time.LocalDate.MAX)
+                    .thenComparing(e -> e.title() != null ? e.title() : "")
+                    .thenComparing(e -> {
+                        if (e.eventId() != null) return e.eventId().toString();
+                        if (e.documentId() != null) return e.documentId().toString();
+                        return "";
+                    });
+
+    private final TimelineEventRepository eventRepository;
+    private final TimelineEventService timelineEventService;
+    private final DocumentService documentService;
+    private final PersonService personService;
+
+    /**
+     * Assembles the timeline for the given filter. All filters are ANDed.
+     * Throws {@link DomainException} (bad request) when fromYear &gt; toYear.
+     * Throws {@link DomainException} (not found) when personId refers to an unknown person.
+     *
+     * <p>{@code @Transactional(readOnly=true)} is required here — unlike simple scalar reads,
+     * this method accesses lazy collections ({@link TimelineEvent#getPersons()},
+     * {@link org.raddatz.familienarchiv.document.Document#getReceivers()}) after the
+     * repository sub-transaction closes. Without this annotation those accesses throw
+     * {@link org.hibernate.LazyInitializationException} in production (constitution §1.6).
+     */
+    @Transactional(readOnly = true)
+    public TimelineDTO assemble(TimelineFilter filter) {
+        if (filter.fromYear() != null && filter.toYear() != null
+                && filter.fromYear() > filter.toYear()) {
+            throw DomainException.badRequest(ErrorCode.VALIDATION_ERROR,
+                    "toYear must not be before fromYear");
+        }
+
+        // Resolve generation person IDs once — used across all three layers
+        Set<UUID> genPersonIds = resolveGenerationPersonIds(filter.generation());
+
+        // ── curated events ───────────────────────────────────────────────────
+        List<TimelineEntryDTO> entries = new ArrayList<>();
+        for (TimelineEvent ev : eventRepository.findAll()) {
+            if (!passesTypeFilter(ev.getType(), filter.type())) continue;
+            if (!passesPersonFilter(ev.getPersons(), filter.personId())) continue;
+            if (!passesGenerationFilter(ev.getPersons(), genPersonIds)) continue;
+            if (!passesYearFilter(ev.getEventDate(), ev.getPrecision(), filter)) continue;
+            entries.add(mapEvent(ev));
+        }
+
+        // ── derived events ───────────────────────────────────────────────────
+        for (TimelineEntryDTO derived : timelineEventService.assembleDerivedEvents()) {
+            if (!passesTypeFilter(derived.type(), filter.type())) continue;
+            if (!passesDerivedPersonFilter(derived.linkedPersonIds(), filter.personId())) continue;
+            if (!passesDerivedGenerationFilter(derived.linkedPersonIds(), genPersonIds)) continue;
+            if (!passesYearFilter(derived.eventDate(), derived.precision(), filter)) continue;
+            entries.add(derived);
+        }
+
+        // ── letters ─────────────────────────────────────────────────────────
+        List<Document> docs = fetchDocuments(filter.personId());
+        for (Document doc : docs) {
+            if (!passesLetterGenerationFilter(doc, genPersonIds)) continue;
+            if (!passesYearFilter(doc.getDocumentDate(), doc.getMetaDatePrecision(), filter)) continue;
+            entries.add(mapDocument(doc));
+        }
+
+        return bucket(entries);
+    }
+
+    // ─── Bucketing ───────────────────────────────────────────────────────────
+
+    Map<Integer, List<TimelineEntryDTO>> bucketByYear(List<TimelineEntryDTO> entries) {
+        Map<Integer, List<TimelineEntryDTO>> map = new TreeMap<>();
+        for (TimelineEntryDTO e : entries) {
+            if (e.eventDate() == null || e.precision() == DatePrecision.UNKNOWN) continue;
+            map.computeIfAbsent(e.eventDate().getYear(), k -> new ArrayList<>()).add(e);
+        }
+        return map;
+    }
+
+    private TimelineDTO bucket(List<TimelineEntryDTO> entries) {
+        List<TimelineEntryDTO> undated = entries.stream()
+                .filter(e -> e.eventDate() == null || e.precision() == DatePrecision.UNKNOWN)
+                .sorted(WITHIN_BAND_ORDER)
+                .toList();
+
+        Map<Integer, List<TimelineEntryDTO>> byYear = bucketByYear(entries);
+        List<TimelineYearDTO> years = byYear.entrySet().stream()
+                .map(e -> new TimelineYearDTO(e.getKey(),
+                        e.getValue().stream().sorted(WITHIN_BAND_ORDER).toList()))
+                .toList();
+
+        return new TimelineDTO(years, undated);
+    }
+
+    // ─── Document fetch (global vs personId path) ────────────────────────────
+
+    private List<Document> fetchDocuments(UUID personId) {
+        if (personId == null) {
+            return documentService.getAllForTimeline();
+        }
+        // personId path: validate existence, then union sender+receiver (dedup by id)
+        personService.getById(personId);
+        Map<UUID, Document> seen = new LinkedHashMap<>();
+        for (Document d : documentService.getDocumentsBySender(personId)) seen.put(d.getId(), d);
+        for (Document d : documentService.getDocumentsByReceiver(personId)) seen.putIfAbsent(d.getId(), d);
+        return new ArrayList<>(seen.values());
+    }
+
+    // ─── Filter predicates ───────────────────────────────────────────────────
+
+    private boolean passesTypeFilter(EventType entryType, EventType filterType) {
+        return filterType == null || filterType == entryType;
+    }
+
+    private boolean passesYearFilter(java.time.LocalDate date, DatePrecision precision, TimelineFilter filter) {
+        if (date == null || precision == DatePrecision.UNKNOWN) return true; // undated → always passes
+        int year = date.getYear();
+        if (filter.fromYear() != null && year < filter.fromYear()) return false;
+        if (filter.toYear() != null && year > filter.toYear()) return false;
+        return true;
+    }
+
+    private boolean passesPersonFilter(Set<Person> persons, UUID personId) {
+        if (personId == null) return true;
+        return persons != null && persons.stream().anyMatch(p -> personId.equals(p.getId()));
+    }
+
+    private boolean passesDerivedPersonFilter(List<UUID> linkedIds, UUID personId) {
+        if (personId == null) return true;
+        return linkedIds != null && linkedIds.contains(personId);
+    }
+
+    private Set<UUID> resolveGenerationPersonIds(Integer generation) {
+        if (generation == null) return null;
+        return personService.getPersonsByGeneration(generation).stream()
+                .map(Person::getId)
+                .collect(Collectors.toSet());
+    }
+
+    private boolean passesGenerationFilter(Set<Person> persons, Set<UUID> genPersonIds) {
+        if (genPersonIds == null) return true;
+        if (persons == null || persons.isEmpty()) return false;
+        return persons.stream().anyMatch(p -> genPersonIds.contains(p.getId()));
+    }
+
+    private boolean passesDerivedGenerationFilter(List<UUID> linkedIds, Set<UUID> genPersonIds) {
+        if (genPersonIds == null) return true;
+        if (linkedIds == null || linkedIds.isEmpty()) return false;
+        return linkedIds.stream().anyMatch(genPersonIds::contains);
+    }
+
+    private boolean passesLetterGenerationFilter(Document doc, Set<UUID> genPersonIds) {
+        if (genPersonIds == null) return true;
+        Person sender = doc.getSender();
+        if (sender != null && genPersonIds.contains(sender.getId())) return true;
+        Set<Person> receivers = doc.getReceivers();
+        if (receivers != null) {
+            return receivers.stream().anyMatch(r -> genPersonIds.contains(r.getId()));
+        }
+        return false;
+    }
+
+    // ─── Mapping ─────────────────────────────────────────────────────────────
+
+    private TimelineEntryDTO mapEvent(TimelineEvent ev) {
+        List<UUID> personIds = ev.getPersons() == null ? List.of()
+                : ev.getPersons().stream().map(Person::getId).toList();
+        return new TimelineEntryDTO(
+                Kind.EVENT,
+                ev.getPrecision(),
+                false,
+                "",
+                "",
+                ev.getEventDate(),
+                ev.getEventDateEnd(),
+                ev.getTitle(),
+                ev.getType(),
+                ev.getId(),
+                null,
+                personIds,
+                null
+        );
+    }
+
+    private TimelineEntryDTO mapDocument(Document doc) {
+        return new TimelineEntryDTO(
+                Kind.LETTER,
+                doc.getMetaDatePrecision(),
+                false,
+                resolveSenderName(doc),
+                resolveReceiverName(doc),
+                doc.getDocumentDate(),
+                null,
+                doc.getTitle(),
+                null,
+                null,
+                doc.getId(),
+                List.of(),
+                null
+        );
+    }
+
+    private String resolveSenderName(Document doc) {
+        if (doc.getSender() != null) return doc.getSender().getDisplayName();
+        String text = doc.getSenderText();
+        return (text != null && !text.isBlank()) ? text : "";
+    }
+
+    private String resolveReceiverName(Document doc) {
+        Set<Person> receivers = doc.getReceivers();
+        if (receivers != null && !receivers.isEmpty()) {
+            return receivers.stream().findFirst().map(Person::getDisplayName).orElse("");
+        }
+        String text = doc.getReceiverText();
+        return (text != null && !text.isBlank()) ? text : "";
+    }
+
+    private static int precisionRank(DatePrecision precision) {
+        if (precision == null) return 0;
+        return switch (precision) {
+            case DAY -> 5;
+            case MONTH -> 4;
+            case SEASON -> 3;
+            case YEAR -> 2;
+            case APPROX -> 1;
+            default -> 0;
+        };
+    }
+}

backend/src/main/java/org/raddatz/familienarchiv/timeline/TimelineYearDTO.java

@@ -0,0 +1,12 @@
+package org.raddatz.familienarchiv.timeline;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+import java.util.List;
+
+/** One year's worth of timeline entries, sorted by {@link TimelineService#WITHIN_BAND_ORDER}. */
+public record TimelineYearDTO(
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) int year,
+        @Schema(requiredMode = Schema.RequiredMode.REQUIRED) List<TimelineEntryDTO> entries
+) {
+}

backend/src/test/java/org/raddatz/familienarchiv/document/DocumentServiceTest.java

@@ -2943,4 +2943,17 @@ class DocumentServiceTest {
         assertThat(result.buckets()).isEmpty();
         verify(documentRepository, org.mockito.Mockito.never()).findAll(any(Specification.class));
     }
+
+    // --- getAllForTimeline ---
+
+    @Test
+    void getAllForTimeline_delegates_bulk_fetch_to_repository() {
+        Document doc = Document.builder().id(UUID.randomUUID()).title("Brief").build();
+        when(documentRepository.findAllForTimeline()).thenReturn(List.of(doc));
+
+        List<Document> result = documentService.getAllForTimeline();
+
+        assertThat(result).containsExactly(doc);
+        verify(documentRepository).findAllForTimeline();
+    }
 }

backend/src/test/java/org/raddatz/familienarchiv/exception/GlobalExceptionHandlerTest.java

@@ -14,6 +14,9 @@ import org.slf4j.LoggerFactory;
 import org.springframework.dao.DataIntegrityViolationException;
 import org.springframework.dao.IncorrectResultSizeDataAccessException;
 import org.springframework.http.ResponseEntity;
+import org.springframework.orm.ObjectOptimisticLockingFailureException;
+
+import java.util.UUID;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.Mockito.mockStatic;
@@ -103,6 +106,49 @@ class GlobalExceptionHandlerTest {
                 });
     }
 
+    @Test
+    void handleOptimisticLock_returns409_genericConflict_noSentry_noLeak() {
+        // CWE-209 regression: an optimistic-lock failure escaping a service catch must become a
+        // generic 409, never a 500 + Sentry + Hibernate internals. The generic CONFLICT code keeps
+        // it entity-agnostic — NOT TIMELINE_EVENT_CONFLICT, or every future entity's conflict is
+        // mislabeled a timeline one.
+        UUID entityId = UUID.randomUUID();
+        ObjectOptimisticLockingFailureException ex =
+                new ObjectOptimisticLockingFailureException("com.example.SomeEntity", entityId);
+
+        Logger handlerLogger = (Logger) LoggerFactory.getLogger(GlobalExceptionHandler.class);
+        ListAppender<ILoggingEvent> appender = new ListAppender<>();
+        appender.start();
+        handlerLogger.addAppender(appender);
+
+        try (MockedStatic<Sentry> sentryMock = mockStatic(Sentry.class)) {
+            ResponseEntity<GlobalExceptionHandler.ErrorResponse> response = handler.handleOptimisticLock(ex);
+
+            assertThat(response.getStatusCode().value()).isEqualTo(409);
+            assertThat(response.getBody()).isNotNull();
+            assertThat(response.getBody().code()).isEqualTo(ErrorCode.CONFLICT);
+            // Body echoes no persistent-class name, no entity id, no version (enumeration aids).
+            assertThat(response.getBody().message())
+                    .doesNotContain("SomeEntity")
+                    .doesNotContain(entityId.toString());
+
+            // A conflict is not a system fault — no fabricated Sentry alert.
+            sentryMock.verifyNoInteractions();
+        } finally {
+            handlerLogger.detachAppender(appender);
+        }
+
+        assertThat(appender.list)
+                .as("WARN names the persistent class for debuggability")
+                .anySatisfy(e -> {
+                    assertThat(e.getLevel()).isEqualTo(Level.WARN);
+                    assertThat(e.getFormattedMessage()).contains("com.example.SomeEntity");
+                });
+        assertThat(appender.list)
+                .as("but never the entity id (would leak via getMessage())")
+                .noneSatisfy(e -> assertThat(e.getFormattedMessage()).contains(entityId.toString()));
+    }
+
     @Test
     void handleDataIntegrityViolation_logsConstraintName_butNotTheSql() {
         // Debuggability (DevOps): the WARN must name *which* constraint fired so an

backend/src/test/java/org/raddatz/familienarchiv/person/PersonServiceTest.java

@@ -1105,4 +1105,25 @@ class PersonServiceTest {
         assertThat(result.direct()).hasSize(1);
         assertThat(result.partial()).isEmpty();
     }
+
+    // --- getPersonsByGeneration ---
+
+    @Test
+    void getPersonsByGeneration_delegates_to_repository() {
+        Person p = Person.builder().id(UUID.randomUUID()).lastName("Müller").generation(2).build();
+        when(personRepository.findByGeneration(2)).thenReturn(List.of(p));
+
+        List<Person> result = personService.getPersonsByGeneration(2);
+
+        assertThat(result).containsExactly(p);
+    }
+
+    @Test
+    void getPersonsByGeneration_returns_emptyList_when_no_match() {
+        when(personRepository.findByGeneration(99)).thenReturn(List.of());
+
+        List<Person> result = personService.getPersonsByGeneration(99);
+
+        assertThat(result).isEmpty();
+    }
 }

backend/src/test/java/org/raddatz/familienarchiv/shared/ArchitectureTest.java

@@ -100,6 +100,13 @@ class ArchitectureTest {
             .and().resideInAPackage("..audit..")
             .should().dependOnClassesThat(foreignJpaRepositoryFor("audit"));
 
+    @ArchTest
+    static final ArchRule services_only_access_own_domain_repositories_timeline =
+        noClasses()
+            .that().areAnnotatedWith(Service.class)
+            .and().resideInAPackage("..timeline..")
+            .should().dependOnClassesThat(foreignJpaRepositoryFor("timeline"));
+
     // Rule 3: Infrastructure @Configuration classes must not end up scattered in domain packages.
     // Keeps cross-cutting setup (security, async, DB, storage) in dedicated packages
     // where it can be audited and reasoned about independently.

backend/src/test/java/org/raddatz/familienarchiv/timeline/DerivedEventsAssemblyTest.java

@@ -0,0 +1,377 @@
+package org.raddatz.familienarchiv.timeline;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.raddatz.familienarchiv.document.DatePrecision;
+import org.raddatz.familienarchiv.document.DocumentService;
+import org.raddatz.familienarchiv.person.Person;
+import org.raddatz.familienarchiv.person.PersonService;
+import org.raddatz.familienarchiv.person.relationship.PersonRelationship;
+import org.raddatz.familienarchiv.person.relationship.RelationshipService;
+import org.raddatz.familienarchiv.person.relationship.RelationType;
+
+import java.time.LocalDate;
+import java.util.List;
+import java.util.UUID;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.when;
+
+@ExtendWith(MockitoExtension.class)
+class DerivedEventsAssemblyTest {
+
+    @Mock private TimelineEventRepository events;
+    @Mock private PersonService personService;
+    @Mock private DocumentService documentService;
+    @Mock private RelationshipService relationshipService;
+
+    @InjectMocks private TimelineEventService service;
+
+    // --- factory helpers ---
+
+    private Person makePerson(LocalDate birthDate, DatePrecision birthPrecision) {
+        return Person.builder()
+                .id(UUID.randomUUID())
+                .firstName("Anna")
+                .lastName("Müller")
+                .familyMember(true)
+                .birthDate(birthDate)
+                .birthDatePrecision(birthPrecision)
+                .build();
+    }
+
+    private Person makePersonWithDeath(LocalDate deathDate, DatePrecision deathPrecision) {
+        return Person.builder()
+                .id(UUID.randomUUID())
+                .firstName("Hans")
+                .lastName("Raddatz")
+                .familyMember(true)
+                .deathDate(deathDate)
+                .deathDatePrecision(deathPrecision)
+                .build();
+    }
+
+    private Person makePersonWithBoth(
+            LocalDate birthDate, DatePrecision birthPrecision,
+            LocalDate deathDate, DatePrecision deathPrecision) {
+        return Person.builder()
+                .id(UUID.randomUUID())
+                .firstName("Anna")
+                .lastName("Müller")
+                .familyMember(true)
+                .birthDate(birthDate)
+                .birthDatePrecision(birthPrecision)
+                .deathDate(deathDate)
+                .deathDatePrecision(deathPrecision)
+                .build();
+    }
+
+    private Person makeNonFamilyPerson(LocalDate birthDate, DatePrecision precision) {
+        return Person.builder()
+                .id(UUID.randomUUID())
+                .firstName("Anna")
+                .lastName("Müller")
+                .familyMember(false)
+                .birthDate(birthDate)
+                .birthDatePrecision(precision)
+                .build();
+    }
+
+    private PersonRelationship makeSpouseEdge(Person a, Person b, Integer fromYear) {
+        return PersonRelationship.builder()
+                .id(UUID.randomUUID())
+                .person(a)
+                .relatedPerson(b)
+                .relationType(RelationType.SPOUSE_OF)
+                .fromYear(fromYear)
+                .build();
+    }
+
+    // --- REQ-001: birth events ---
+
+    @Test
+    void should_emit_one_geburt_for_person_with_birthdate() {
+        Person anna = makePerson(LocalDate.of(1901, 3, 12), DatePrecision.DAY);
+        when(personService.findAllFamilyMembers()).thenReturn(List.of(anna));
+        when(relationshipService.findAllSpouseEdges()).thenReturn(List.of());
+
+        List<TimelineEntryDTO> result = service.assembleDerivedEvents();
+
+        assertThat(result).hasSize(1);
+        TimelineEntryDTO event = result.get(0);
+        assertThat(event.derived()).isTrue();
+        assertThat(event.type()).isEqualTo(EventType.PERSONAL);
+        assertThat(event.derivedType()).isEqualTo(DerivedEventType.BIRTH);
+        assertThat(event.eventDate()).isEqualTo(LocalDate.of(1901, 3, 12));
+        assertThat(event.precision()).isEqualTo(DatePrecision.DAY);
+        assertThat(event.title()).isEqualTo(anna.getDisplayName());
+    }
+
+    // --- REQ-003: null birthDate → no Geburt event ---
+
+    @Test
+    void should_emit_zero_tod_when_person_has_birthdate_but_no_deathdate() {
+        Person anna = makePerson(LocalDate.of(1901, 3, 12), DatePrecision.DAY);
+        when(personService.findAllFamilyMembers()).thenReturn(List.of(anna));
+        when(relationshipService.findAllSpouseEdges()).thenReturn(List.of());
+
+        List<TimelineEntryDTO> result = service.assembleDerivedEvents();
+
+        long todCount = result.stream()
+                .filter(e -> e.derivedType() == DerivedEventType.DEATH)
+                .count();
+        assertThat(todCount).isZero();
+    }
+
+    // --- REQ-004: null deathDate → no Tod event ---
+
+    @Test
+    void should_emit_no_events_for_person_with_neither_date() {
+        Person nobody = Person.builder()
+                .id(UUID.randomUUID())
+                .firstName("Hans")
+                .lastName("Raddatz")
+                .familyMember(true)
+                .build();
+        when(personService.findAllFamilyMembers()).thenReturn(List.of(nobody));
+        when(relationshipService.findAllSpouseEdges()).thenReturn(List.of());
+
+        List<TimelineEntryDTO> result = service.assembleDerivedEvents();
+
+        assertThat(result).isEmpty();
+    }
+
+    // --- REQ-002: death events ---
+
+    @Test
+    void should_emit_one_tod_for_person_with_deathdate() {
+        Person hans = makePersonWithDeath(LocalDate.of(1965, 7, 4), DatePrecision.DAY);
+        when(personService.findAllFamilyMembers()).thenReturn(List.of(hans));
+        when(relationshipService.findAllSpouseEdges()).thenReturn(List.of());
+
+        List<TimelineEntryDTO> result = service.assembleDerivedEvents();
+
+        assertThat(result).hasSize(1);
+        TimelineEntryDTO event = result.get(0);
+        assertThat(event.derived()).isTrue();
+        assertThat(event.type()).isEqualTo(EventType.PERSONAL);
+        assertThat(event.derivedType()).isEqualTo(DerivedEventType.DEATH);
+        assertThat(event.eventDate()).isEqualTo(LocalDate.of(1965, 7, 4));
+        assertThat(event.precision()).isEqualTo(DatePrecision.DAY);
+        assertThat(event.title()).isEqualTo(hans.getDisplayName());
+    }
+
+    // --- REQ-002 + REQ-003 combined ---
+
+    @Test
+    void should_emit_one_tod_and_zero_geburt_for_person_with_deathdate_only() {
+        Person hans = makePersonWithDeath(LocalDate.of(1965, 7, 4), DatePrecision.YEAR);
+        when(personService.findAllFamilyMembers()).thenReturn(List.of(hans));
+        when(relationshipService.findAllSpouseEdges()).thenReturn(List.of());
+
+        List<TimelineEntryDTO> result = service.assembleDerivedEvents();
+
+        assertThat(result).hasSize(1);
+        assertThat(result.get(0).derivedType()).isEqualTo(DerivedEventType.DEATH);
+    }
+
+    // --- REQ-005: Heirat with fromYear ---
+
+    @Test
+    void should_emit_one_heirat_for_spouse_edge_with_fromYear() {
+        Person anna = makePerson(null, DatePrecision.UNKNOWN);
+        Person hans = makePersonWithDeath(null, DatePrecision.UNKNOWN);
+        PersonRelationship edge = makeSpouseEdge(anna, hans, 1930);
+        when(personService.findAllFamilyMembers()).thenReturn(List.of(anna, hans));
+        when(relationshipService.findAllSpouseEdges()).thenReturn(List.of(edge));
+
+        List<TimelineEntryDTO> result = service.assembleDerivedEvents();
+
+        List<TimelineEntryDTO> heiraten = result.stream()
+                .filter(e -> e.derivedType() == DerivedEventType.MARRIAGE)
+                .toList();
+        assertThat(heiraten).hasSize(1);
+        TimelineEntryDTO heirat = heiraten.get(0);
+        assertThat(heirat.derived()).isTrue();
+        assertThat(heirat.type()).isEqualTo(EventType.PERSONAL);
+        assertThat(heirat.derivedType()).isEqualTo(DerivedEventType.MARRIAGE);
+        assertThat(heirat.eventDate()).isEqualTo(LocalDate.of(1930, 1, 1));
+        assertThat(heirat.precision()).isEqualTo(DatePrecision.YEAR);
+    }
+
+    // --- REQ-006: Heirat with null fromYear → emitted with UNKNOWN precision ---
+
+    @Test
+    void should_emit_unknown_precision_heirat_when_fromYear_is_null() {
+        Person anna = makePerson(null, DatePrecision.UNKNOWN);
+        Person hans = makePersonWithDeath(null, DatePrecision.UNKNOWN);
+        PersonRelationship edge = makeSpouseEdge(anna, hans, null);
+        when(personService.findAllFamilyMembers()).thenReturn(List.of(anna, hans));
+        when(relationshipService.findAllSpouseEdges()).thenReturn(List.of(edge));
+
+        List<TimelineEntryDTO> result = service.assembleDerivedEvents();
+
+        List<TimelineEntryDTO> heiraten = result.stream()
+                .filter(e -> e.derivedType() == DerivedEventType.MARRIAGE)
+                .toList();
+        assertThat(heiraten).hasSize(1);
+        TimelineEntryDTO heirat = heiraten.get(0);
+        assertThat(heirat.eventDate()).isNull();
+        assertThat(heirat.precision()).isEqualTo(DatePrecision.UNKNOWN);
+    }
+
+    // --- REQ-007: exactly one Heirat per SPOUSE_OF edge (dedup) ---
+
+    @Test
+    void should_emit_exactly_one_heirat_when_both_spouses_in_scope() {
+        Person anna = makePerson(null, DatePrecision.UNKNOWN);
+        Person hans = makePerson(null, DatePrecision.UNKNOWN);
+        PersonRelationship edge = makeSpouseEdge(anna, hans, 1930);
+        when(personService.findAllFamilyMembers()).thenReturn(List.of(anna, hans));
+        when(relationshipService.findAllSpouseEdges()).thenReturn(List.of(edge));
+
+        List<TimelineEntryDTO> result = service.assembleDerivedEvents();
+
+        long heiratCount = result.stream()
+                .filter(e -> e.derivedType() == DerivedEventType.MARRIAGE)
+                .count();
+        assertThat(heiratCount).isEqualTo(1);
+    }
+
+    @Test
+    void should_emit_two_heirat_for_person_married_to_two_partners() {
+        Person anna = makePerson(null, DatePrecision.UNKNOWN);
+        Person hans = makePerson(null, DatePrecision.UNKNOWN);
+        Person karl = makePerson(null, DatePrecision.UNKNOWN);
+        PersonRelationship edge1 = makeSpouseEdge(anna, hans, 1930);
+        PersonRelationship edge2 = makeSpouseEdge(anna, karl, 1945);
+        when(personService.findAllFamilyMembers()).thenReturn(List.of(anna, hans, karl));
+        when(relationshipService.findAllSpouseEdges()).thenReturn(List.of(edge1, edge2));
+
+        List<TimelineEntryDTO> result = service.assembleDerivedEvents();
+
+        long heiratCount = result.stream()
+                .filter(e -> e.derivedType() == DerivedEventType.MARRIAGE)
+                .count();
+        assertThat(heiratCount).isEqualTo(2);
+    }
+
+    // --- REQ-001 precision pass-through ---
+
+    @Test
+    void should_pass_birth_precision_through_unchanged() {
+        Person anna = makePerson(LocalDate.of(1901, 3, 12), DatePrecision.DAY);
+        when(personService.findAllFamilyMembers()).thenReturn(List.of(anna));
+        when(relationshipService.findAllSpouseEdges()).thenReturn(List.of());
+
+        List<TimelineEntryDTO> result = service.assembleDerivedEvents();
+
+        assertThat(result).hasSize(1);
+        assertThat(result.get(0).precision()).isEqualTo(DatePrecision.DAY);
+    }
+
+    // --- REQ-008: synthetic prefixed ids, never UUID ---
+
+    @Test
+    void should_mint_prefixed_synthetic_ids_never_uuid() {
+        Person anna = makePerson(LocalDate.of(1901, 3, 12), DatePrecision.DAY);
+        when(personService.findAllFamilyMembers()).thenReturn(List.of(anna));
+        when(relationshipService.findAllSpouseEdges()).thenReturn(List.of());
+
+        List<TimelineEntryDTO> result = service.assembleDerivedEvents();
+
+        assertThat(result).hasSize(1);
+        TimelineEntryDTO entry = result.get(0);
+        assertThat(entry.derived()).isTrue();
+        assertThat(entry.eventId()).isNull();
+        assertThat(entry.documentId()).isNull();
+    }
+
+    // --- REQ-010: display names on Heirat ---
+
+    @Test
+    void should_emit_heirat_with_displayname_for_both_spouses() {
+        Person anna = makePerson(null, DatePrecision.UNKNOWN);
+        Person hans = makePersonWithDeath(null, DatePrecision.UNKNOWN);
+        PersonRelationship edge = makeSpouseEdge(anna, hans, 1930);
+        when(personService.findAllFamilyMembers()).thenReturn(List.of(anna, hans));
+        when(relationshipService.findAllSpouseEdges()).thenReturn(List.of(edge));
+
+        List<TimelineEntryDTO> heiraten = service.assembleDerivedEvents().stream()
+                .filter(e -> e.derivedType() == DerivedEventType.MARRIAGE)
+                .toList();
+
+        assertThat(heiraten).hasSize(1);
+        TimelineEntryDTO heirat = heiraten.get(0);
+        assertThat(heirat.title()).isNotNull().isNotBlank();
+        assertThat(heirat.linkedPersonIds()).hasSize(2);
+    }
+
+    // --- REQ-007 note: assumption/documentation test ---
+
+    @Test
+    void self_spouse_edge_invariant_is_enforced_by_db_constraint() {
+        // Assumption test — documents that the DB constraint prevents self-edges;
+        // the service does not guard this itself.
+        // The unique_spouse_pair index (V55) using LEAST/GREATEST is the authoritative guard.
+        // This test verifies that if an edge were somehow inserted (impossible in prod),
+        // the service would still produce one event (not zero or an exception).
+        Person anna = makePerson(null, DatePrecision.UNKNOWN);
+        PersonRelationship selfEdge = makeSpouseEdge(anna, anna, 1930);
+        when(personService.findAllFamilyMembers()).thenReturn(List.of(anna));
+        when(relationshipService.findAllSpouseEdges()).thenReturn(List.of(selfEdge));
+
+        List<TimelineEntryDTO> result = service.assembleDerivedEvents();
+
+        long heiratCount = result.stream()
+                .filter(e -> e.derivedType() == DerivedEventType.MARRIAGE)
+                .count();
+        assertThat(heiratCount).isEqualTo(1);
+    }
+
+    // --- REQ-012: non-family-member persons excluded from Geburt/Tod ---
+
+    @Test
+    void should_exclude_non_family_member_persons_from_derived_events() {
+        Person nonMember = makeNonFamilyPerson(LocalDate.of(1901, 3, 12), DatePrecision.DAY);
+        when(personService.findAllFamilyMembers()).thenReturn(List.of());
+        when(relationshipService.findAllSpouseEdges()).thenReturn(List.of());
+
+        List<TimelineEntryDTO> result = service.assembleDerivedEvents();
+
+        assertThat(result).isEmpty();
+    }
+
+    // --- REQ-013: Heirat emitted even when one spouse has familyMember=false ---
+
+    @Test
+    void should_emit_heirat_when_one_spouse_is_not_family_member() {
+        Person anna = makePerson(null, DatePrecision.UNKNOWN);
+        Person nonMember = makeNonFamilyPerson(null, DatePrecision.UNKNOWN);
+        PersonRelationship edge = makeSpouseEdge(anna, nonMember, 1930);
+        when(personService.findAllFamilyMembers()).thenReturn(List.of(anna));
+        when(relationshipService.findAllSpouseEdges()).thenReturn(List.of(edge));
+
+        List<TimelineEntryDTO> result = service.assembleDerivedEvents();
+
+        long heiratCount = result.stream()
+                .filter(e -> e.derivedType() == DerivedEventType.MARRIAGE)
+                .count();
+        assertThat(heiratCount).isEqualTo(1);
+    }
+
+    // --- REQ-014: empty family-member list → empty result, no error ---
+
+    @Test
+    void should_emit_zero_events_when_no_family_members() {
+        when(personService.findAllFamilyMembers()).thenReturn(List.of());
+        when(relationshipService.findAllSpouseEdges()).thenReturn(List.of());
+
+        List<TimelineEntryDTO> result = service.assembleDerivedEvents();
+
+        assertThat(result).isEmpty();
+    }
+}

backend/src/test/java/org/raddatz/familienarchiv/timeline/TimelineControllerTest.java

@@ -0,0 +1,139 @@
+package org.raddatz.familienarchiv.timeline;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.raddatz.familienarchiv.exception.DomainException;
+import org.raddatz.familienarchiv.exception.ErrorCode;
+import org.raddatz.familienarchiv.security.PermissionAspect;
+import org.raddatz.familienarchiv.security.SecurityConfig;
+import org.raddatz.familienarchiv.user.AppUser;
+import org.raddatz.familienarchiv.user.CustomUserDetailsService;
+import org.raddatz.familienarchiv.user.UserService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.aop.AopAutoConfiguration;
+import org.springframework.boot.webmvc.test.autoconfigure.WebMvcTest;
+import org.springframework.context.annotation.Import;
+import org.springframework.test.context.bean.override.mockito.MockitoBean;
+import org.springframework.test.web.servlet.MockMvc;
+
+import java.util.List;
+import java.util.UUID;
+
+import static org.hamcrest.Matchers.is;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+@WebMvcTest(TimelineController.class)
+@Import({SecurityConfig.class, PermissionAspect.class, AopAutoConfiguration.class})
+class TimelineControllerTest {
+
+    @Autowired MockMvc mockMvc;
+
+    @MockitoBean TimelineService timelineService;
+    @MockitoBean UserService userService;
+    @MockitoBean CustomUserDetailsService customUserDetailsService;
+
+    private static final TimelineDTO EMPTY = new TimelineDTO(List.of(), List.of());
+
+    @BeforeEach
+    void resolveDefaultPrincipal() {
+        when(userService.findByEmail("user"))
+                .thenReturn(AppUser.builder().id(UUID.randomUUID()).email("user").build());
+    }
+
+    // ─── Security ─────────────────────────────────────────────────────────────
+
+    @Test
+    void returns_401_when_unauthenticated() throws Exception {
+        // REQ-014
+        mockMvc.perform(get("/api/timeline"))
+                .andExpect(status().isUnauthorized());
+    }
+
+    @Test
+    @org.springframework.security.test.context.support.WithMockUser(authorities = "WRITE_ALL")
+    void returns_403_when_authenticated_without_read_all() throws Exception {
+        // REQ-015
+        mockMvc.perform(get("/api/timeline"))
+                .andExpect(status().isForbidden());
+    }
+
+    @Test
+    @org.springframework.security.test.context.support.WithMockUser(authorities = "READ_ALL")
+    void returns_200_with_read_all_permission() throws Exception {
+        // REQ-001
+        when(timelineService.assemble(any())).thenReturn(EMPTY);
+
+        mockMvc.perform(get("/api/timeline"))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.years").isArray())
+                .andExpect(jsonPath("$.undated").isArray());
+    }
+
+    // ─── Parameter binding ────────────────────────────────────────────────────
+
+    @Test
+    @org.springframework.security.test.context.support.WithMockUser(authorities = "READ_ALL")
+    void valid_params_are_forwarded_to_service() throws Exception {
+        UUID personId = UUID.randomUUID();
+        when(timelineService.assemble(any())).thenReturn(EMPTY);
+
+        mockMvc.perform(get("/api/timeline")
+                        .param("personId", personId.toString())
+                        .param("generation", "2")
+                        .param("type", "HISTORICAL")
+                        .param("fromYear", "1914")
+                        .param("toYear", "1918"))
+                .andExpect(status().isOk());
+
+        verify(timelineService).assemble(new TimelineFilter(personId, 2, EventType.HISTORICAL, 1914, 1918));
+    }
+
+    // ─── Validation errors ────────────────────────────────────────────────────
+
+    @Test
+    @org.springframework.security.test.context.support.WithMockUser(authorities = "READ_ALL")
+    void returns_400_on_bad_type_value() throws Exception {
+        // REQ-018 — Spring enum binding rejects unknown value
+        mockMvc.perform(get("/api/timeline").param("type", "NOT_A_TYPE"))
+                .andExpect(status().isBadRequest());
+    }
+
+    @Test
+    @org.springframework.security.test.context.support.WithMockUser(authorities = "READ_ALL")
+    void returns_400_when_fromYear_greater_than_toYear() throws Exception {
+        // REQ-016 — service throws bad request, controller propagates it
+        when(timelineService.assemble(any()))
+                .thenThrow(DomainException.badRequest(ErrorCode.VALIDATION_ERROR,
+                        "toYear must not be before fromYear"));
+
+        mockMvc.perform(get("/api/timeline")
+                        .param("fromYear", "1920")
+                        .param("toYear", "1914"))
+                .andExpect(status().isBadRequest());
+    }
+
+    @Test
+    @org.springframework.security.test.context.support.WithMockUser(authorities = "READ_ALL")
+    void returns_400_when_generation_is_negative() throws Exception {
+        // REQ-017 — @Min(0) on generation parameter
+        mockMvc.perform(get("/api/timeline").param("generation", "-1"))
+                .andExpect(status().isBadRequest());
+    }
+
+    @Test
+    @org.springframework.security.test.context.support.WithMockUser(authorities = "READ_ALL")
+    void returns_404_when_person_not_found() throws Exception {
+        // REQ-019
+        when(timelineService.assemble(any()))
+                .thenThrow(DomainException.notFound(ErrorCode.PERSON_NOT_FOUND, "Person not found"));
+
+        mockMvc.perform(get("/api/timeline").param("personId", UUID.randomUUID().toString()))
+                .andExpect(status().isNotFound())
+                .andExpect(jsonPath("$.code", is("PERSON_NOT_FOUND")));
+    }
+}

backend/src/test/java/org/raddatz/familienarchiv/timeline/TimelineEventControllerTest.java

@@ -0,0 +1,273 @@
+package org.raddatz.familienarchiv.timeline;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.raddatz.familienarchiv.exception.DomainException;
+import org.raddatz.familienarchiv.exception.ErrorCode;
+import org.raddatz.familienarchiv.security.PermissionAspect;
+import org.raddatz.familienarchiv.security.SecurityConfig;
+import org.raddatz.familienarchiv.user.AppUser;
+import org.raddatz.familienarchiv.user.CustomUserDetailsService;
+import org.raddatz.familienarchiv.user.UserService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.aop.AopAutoConfiguration;
+import org.springframework.boot.webmvc.test.autoconfigure.WebMvcTest;
+import org.springframework.context.annotation.Import;
+import org.springframework.http.MediaType;
+import org.springframework.security.test.context.support.WithMockUser;
+import org.springframework.test.context.bean.override.mockito.MockitoBean;
+import org.springframework.test.web.servlet.MockMvc;
+
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.util.List;
+import java.util.UUID;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+import static org.springframework.security.test.web.servlet.request.SecurityMockMvcRequestPostProcessors.csrf;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.delete;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.put;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+@WebMvcTest(TimelineEventController.class)
+@Import({SecurityConfig.class, PermissionAspect.class, AopAutoConfiguration.class})
+class TimelineEventControllerTest {
+
+    @Autowired MockMvc mockMvc;
+
+    @MockitoBean TimelineEventService timelineEventService;
+    @MockitoBean UserService userService;
+    @MockitoBean CustomUserDetailsService customUserDetailsService;
+
+    private static final String VALID_JSON =
+            "{\"title\":\"Hochzeit\",\"type\":\"PERSONAL\",\"eventDate\":\"1914-07-28\"}";
+
+    /** Default principal resolution for @WithMockUser's "user"; capture tests override with a known id. */
+    @BeforeEach
+    void resolveDefaultPrincipal() {
+        when(userService.findByEmail("user"))
+                .thenReturn(AppUser.builder().id(UUID.randomUUID()).email("user").build());
+    }
+
+    private TimelineEventView sampleView() {
+        return new TimelineEventView(
+                UUID.randomUUID(), "Hochzeit", EventType.PERSONAL, LocalDate.of(1914, 1, 1),
+                org.raddatz.familienarchiv.document.DatePrecision.YEAR, null, null, 0L,
+                UUID.randomUUID(), LocalDateTime.now(), UUID.randomUUID(), LocalDateTime.now(),
+                List.of(), List.of());
+    }
+
+    // ─── POST /api/timeline/events ───────────────────────────────────────────
+
+    @Test
+    void create_returns401_whenUnauthenticated() throws Exception {
+        mockMvc.perform(post("/api/timeline/events").with(csrf())
+                        .contentType(MediaType.APPLICATION_JSON).content(VALID_JSON))
+                .andExpect(status().isUnauthorized());
+    }
+
+    @Test
+    @WithMockUser(authorities = "READ_ALL")
+    void create_returns403_whenOnlyReadAll() throws Exception {
+        mockMvc.perform(post("/api/timeline/events").with(csrf())
+                        .contentType(MediaType.APPLICATION_JSON).content(VALID_JSON))
+                .andExpect(status().isForbidden());
+    }
+
+    @Test
+    @WithMockUser(authorities = "WRITE_ALL")
+    void create_returns201_andViewBody_whenWriteAll() throws Exception {
+        when(timelineEventService.create(any(), any())).thenReturn(sampleView());
+
+        mockMvc.perform(post("/api/timeline/events").with(csrf())
+                        .contentType(MediaType.APPLICATION_JSON).content(VALID_JSON))
+                .andExpect(status().isCreated())
+                .andExpect(jsonPath("$.title").value("Hochzeit"))
+                .andExpect(jsonPath("$.version").value(0));
+    }
+
+    // ─── PUT /api/timeline/events/{id} ───────────────────────────────────────
+
+    @Test
+    void update_returns401_whenUnauthenticated() throws Exception {
+        mockMvc.perform(put("/api/timeline/events/" + UUID.randomUUID()).with(csrf())
+                        .contentType(MediaType.APPLICATION_JSON).content(VALID_JSON))
+                .andExpect(status().isUnauthorized());
+    }
+
+    @Test
+    @WithMockUser(authorities = "READ_ALL")
+    void update_returns403_whenOnlyReadAll() throws Exception {
+        mockMvc.perform(put("/api/timeline/events/" + UUID.randomUUID()).with(csrf())
+                        .contentType(MediaType.APPLICATION_JSON).content(VALID_JSON))
+                .andExpect(status().isForbidden());
+    }
+
+    @Test
+    @WithMockUser(authorities = "WRITE_ALL")
+    void update_returns200_andViewBody_whenWriteAll() throws Exception {
+        when(timelineEventService.update(any(), any(), any())).thenReturn(sampleView());
+
+        mockMvc.perform(put("/api/timeline/events/" + UUID.randomUUID()).with(csrf())
+                        .contentType(MediaType.APPLICATION_JSON).content(VALID_JSON))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.title").value("Hochzeit"));
+    }
+
+    // ─── DELETE /api/timeline/events/{id} ────────────────────────────────────
+
+    @Test
+    void delete_returns401_whenUnauthenticated() throws Exception {
+        mockMvc.perform(delete("/api/timeline/events/" + UUID.randomUUID()).with(csrf()))
+                .andExpect(status().isUnauthorized());
+    }
+
+    @Test
+    @WithMockUser(authorities = "READ_ALL")
+    void delete_returns403_whenOnlyReadAll() throws Exception {
+        mockMvc.perform(delete("/api/timeline/events/" + UUID.randomUUID()).with(csrf()))
+                .andExpect(status().isForbidden());
+    }
+
+    @Test
+    @WithMockUser(authorities = "WRITE_ALL")
+    void delete_returns204_whenWriteAll() throws Exception {
+        mockMvc.perform(delete("/api/timeline/events/" + UUID.randomUUID()).with(csrf()))
+                .andExpect(status().isNoContent());
+    }
+
+    // ─── GET /api/timeline/events/{id} ───────────────────────────────────────
+
+    @Test
+    void getEvent_returns401_whenUnauthenticated() throws Exception {
+        mockMvc.perform(get("/api/timeline/events/" + UUID.randomUUID()))
+                .andExpect(status().isUnauthorized());
+    }
+
+    @Test
+    @WithMockUser
+    void getEvent_returns200_whenAuthenticated() throws Exception {
+        when(timelineEventService.getEvent(any())).thenReturn(sampleView());
+
+        mockMvc.perform(get("/api/timeline/events/" + UUID.randomUUID()))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.title").value("Hochzeit"));
+    }
+
+    @Test
+    @WithMockUser
+    void getEvent_returns404_whenMissing() throws Exception {
+        when(timelineEventService.getEvent(any()))
+                .thenThrow(DomainException.notFound(ErrorCode.TIMELINE_EVENT_NOT_FOUND, "not found"));
+
+        mockMvc.perform(get("/api/timeline/events/" + UUID.randomUUID()))
+                .andExpect(status().isNotFound());
+    }
+
+    // ─── service-thrown link errors map to status ────────────────────────────
+
+    @Test
+    @WithMockUser(authorities = "WRITE_ALL")
+    void create_returns404_whenServiceThrowsPersonNotFound() throws Exception {
+        when(timelineEventService.create(any(), any()))
+                .thenThrow(DomainException.notFound(ErrorCode.PERSON_NOT_FOUND, "One or more person IDs not found"));
+
+        mockMvc.perform(post("/api/timeline/events").with(csrf())
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content("{\"title\":\"Hochzeit\",\"type\":\"PERSONAL\",\"eventDate\":\"1914-07-28\",\"personIds\":[\""
+                                + UUID.randomUUID() + "\"]}"))
+                .andExpect(status().isNotFound());
+    }
+
+    // ─── Bean Validation 400s carry code VALIDATION_ERROR (R1) ───────────────
+
+    @Test
+    @WithMockUser(authorities = "WRITE_ALL")
+    void create_returns400_VALIDATION_ERROR_whenTitleBlank() throws Exception {
+        mockMvc.perform(post("/api/timeline/events").with(csrf())
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content("{\"title\":\"  \",\"type\":\"PERSONAL\",\"eventDate\":\"1914-07-28\"}"))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value("VALIDATION_ERROR"));
+    }
+
+    @Test
+    @WithMockUser(authorities = "WRITE_ALL")
+    void create_returns400_VALIDATION_ERROR_whenTypeNull() throws Exception {
+        mockMvc.perform(post("/api/timeline/events").with(csrf())
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content("{\"title\":\"Hochzeit\",\"eventDate\":\"1914-07-28\"}"))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value("VALIDATION_ERROR"));
+    }
+
+    @Test
+    @WithMockUser(authorities = "WRITE_ALL")
+    void create_returns400_VALIDATION_ERROR_whenDescriptionTooLong() throws Exception {
+        String description = "x".repeat(5001);
+        mockMvc.perform(post("/api/timeline/events").with(csrf())
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content("{\"title\":\"Hochzeit\",\"type\":\"PERSONAL\",\"eventDate\":\"1914-07-28\",\"description\":\""
+                                + description + "\"}"))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value("VALIDATION_ERROR"));
+    }
+
+    @Test
+    @WithMockUser(authorities = "WRITE_ALL")
+    void create_returns400_VALIDATION_ERROR_whenTooManyPersonIds() throws Exception {
+        String ids = Stream.generate(() -> "\"" + UUID.randomUUID() + "\"").limit(51).collect(Collectors.joining(","));
+        mockMvc.perform(post("/api/timeline/events").with(csrf())
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content("{\"title\":\"Hochzeit\",\"type\":\"PERSONAL\",\"eventDate\":\"1914-07-28\",\"personIds\":["
+                                + ids + "]}"))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value("VALIDATION_ERROR"));
+    }
+
+    // ─── actorId is the resolved session principal, not a body field (both write paths) ──
+
+    @Test
+    @WithMockUser(username = "curator@example.com", authorities = "WRITE_ALL")
+    void create_passesResolvedPrincipalIdAsActor_ignoringBodyCreatedBy() throws Exception {
+        UUID principalId = UUID.randomUUID();
+        when(userService.findByEmail("curator@example.com"))
+                .thenReturn(AppUser.builder().id(principalId).email("curator@example.com").build());
+        when(timelineEventService.create(any(), any())).thenReturn(sampleView());
+
+        // body carries a forged createdBy — it must be ignored, actor comes from the principal
+        mockMvc.perform(post("/api/timeline/events").with(csrf())
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content("{\"title\":\"Hochzeit\",\"type\":\"PERSONAL\",\"eventDate\":\"1914-07-28\",\"createdBy\":\""
+                                + UUID.randomUUID() + "\"}"))
+                .andExpect(status().isCreated());
+
+        verify(timelineEventService).create(any(), eq(principalId));
+    }
+
+    @Test
+    @WithMockUser(username = "curator@example.com", authorities = "WRITE_ALL")
+    void update_passesResolvedPrincipalIdAsActor_ignoringBodyUpdatedBy() throws Exception {
+        UUID principalId = UUID.randomUUID();
+        UUID eventId = UUID.randomUUID();
+        when(userService.findByEmail("curator@example.com"))
+                .thenReturn(AppUser.builder().id(principalId).email("curator@example.com").build());
+        when(timelineEventService.update(any(), any(), any())).thenReturn(sampleView());
+
+        mockMvc.perform(put("/api/timeline/events/" + eventId).with(csrf())
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content("{\"title\":\"Hochzeit\",\"type\":\"PERSONAL\",\"eventDate\":\"1914-07-28\",\"updatedBy\":\""
+                                + UUID.randomUUID() + "\"}"))
+                .andExpect(status().isOk());
+
+        verify(timelineEventService).update(eq(eventId), any(), eq(principalId));
+    }
+}

backend/src/test/java/org/raddatz/familienarchiv/timeline/TimelineEventServiceIntegrationTest.java

@@ -0,0 +1,109 @@
+package org.raddatz.familienarchiv.timeline;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import jakarta.persistence.EntityManager;
+import jakarta.persistence.PersistenceContext;
+import org.junit.jupiter.api.Test;
+import org.raddatz.familienarchiv.PostgresContainerConfig;
+import org.raddatz.familienarchiv.document.Document;
+import org.raddatz.familienarchiv.document.DocumentRepository;
+import org.raddatz.familienarchiv.document.DocumentStatus;
+import org.raddatz.familienarchiv.exception.DomainException;
+import org.raddatz.familienarchiv.exception.ErrorCode;
+import org.raddatz.familienarchiv.person.Person;
+import org.raddatz.familienarchiv.person.PersonRepository;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.context.annotation.Import;
+import org.springframework.test.context.ActiveProfiles;
+import org.springframework.test.context.bean.override.mockito.MockitoBean;
+import org.springframework.transaction.annotation.Transactional;
+import software.amazon.awssdk.services.s3.S3Client;
+
+import java.time.LocalDate;
+import java.util.List;
+import java.util.UUID;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+/**
+ * Service-level integration scope the entity/DB tests ({@link TimelineEventTest}) don't reach: the
+ * in-transaction view assembly survives a context clear (the {@code @Transactional(readOnly = true)}
+ * LazyInit guard), the serialized view leaks no curator-internal fields, and the {@code @Version}
+ * optimistic lock engages end-to-end (the Mockito test only proves the catch branch). Real Postgres
+ * (V77 CHECK constraints are Postgres-specific) via {@link PostgresContainerConfig}.
+ */
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.NONE)
+@ActiveProfiles("test")
+@Import(PostgresContainerConfig.class)
+@Transactional
+class TimelineEventServiceIntegrationTest {
+
+    @MockitoBean S3Client s3Client;
+    @Autowired TimelineEventService service;
+    @Autowired PersonRepository personRepository;
+    @Autowired DocumentRepository documentRepository;
+    @PersistenceContext EntityManager em;
+
+    // Built locally — the webEnvironment=NONE context has no auto-configured ObjectMapper bean.
+    // findAndRegisterModules() pulls in JavaTimeModule so the view's LocalDate/LocalDateTime serialize.
+    private final ObjectMapper objectMapper = new ObjectMapper().findAndRegisterModules();
+
+    private TimelineEventRequest request(String title, Long version, List<UUID> personIds, List<UUID> documentIds) {
+        return new TimelineEventRequest(title, EventType.PERSONAL, LocalDate.of(1914, 7, 28),
+                null, null, null, version, personIds, documentIds);
+    }
+
+    @Test
+    void getEvent_after_context_clear_populates_links_and_leaks_no_internal_fields() throws Exception {
+        Person anna = personRepository.save(Person.builder()
+                .firstName("Anna").lastName("Müller").notes("GEHEIM-NOTIZ").provisional(true).build());
+        Document letter = documentRepository.save(Document.builder()
+                .title("Brief an Anna").originalFilename("brief.pdf").status(DocumentStatus.UPLOADED).build());
+        UUID eventId = service.create(
+                request("Hochzeit", null, List.of(anna.getId()), List.of(letter.getId())), UUID.randomUUID()).id();
+        em.flush();
+        em.clear();
+
+        // Fresh read — NOT the create return value (that view was assembled while the entity was
+        // managed). Only a separate read after the clear proves the readOnly LazyInit guard.
+        TimelineEventView fresh = service.getEvent(eventId);
+
+        assertThat(fresh.persons()).singleElement().satisfies(p -> {
+            assertThat(p.firstName()).isEqualTo("Anna");
+            assertThat(p.lastName()).isEqualTo("Müller");
+        });
+        assertThat(fresh.documents()).singleElement().satisfies(d ->
+                assertThat(d.title()).isEqualTo("Brief an Anna"));
+
+        // Assert on the SERIALIZED JSON: a getter re-introducing a leaked field later would slip
+        // past a field-level check.
+        String json = objectMapper.writeValueAsString(fresh);
+        assertThat(json)
+                .doesNotContain("GEHEIM-NOTIZ")
+                .doesNotContain("notes")
+                .doesNotContain("provisional")
+                .doesNotContain("password");
+    }
+
+    @Test
+    void concurrent_update_with_stale_version_yields_TIMELINE_EVENT_CONFLICT() {
+        UUID editorA = UUID.randomUUID();
+        UUID editorB = UUID.randomUUID();
+        UUID eventId = service.create(request("Original", null, null, null), editorA).id();
+        em.flush();
+        em.clear();
+
+        // Editor A saves with the version they last saw (0) → succeeds, version advances to 1.
+        service.update(eventId, request("Edit A", 0L, null, null), editorA);
+        em.flush();
+        em.clear();
+
+        // Editor B still holds the stale version 0 → the versioned UPDATE matches no row → 409.
+        assertThatThrownBy(() -> service.update(eventId, request("Edit B", 0L, null, null), editorB))
+                .isInstanceOf(DomainException.class)
+                .extracting(e -> ((DomainException) e).getCode())
+                .isEqualTo(ErrorCode.TIMELINE_EVENT_CONFLICT);
+    }
+}

backend/src/test/java/org/raddatz/familienarchiv/timeline/TimelineEventServiceTest.java

@@ -0,0 +1,453 @@
+package org.raddatz.familienarchiv.timeline;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.raddatz.familienarchiv.document.DatePrecision;
+import org.raddatz.familienarchiv.document.Document;
+import org.raddatz.familienarchiv.document.DocumentService;
+import org.raddatz.familienarchiv.exception.DomainException;
+import org.raddatz.familienarchiv.exception.ErrorCode;
+import org.raddatz.familienarchiv.person.Person;
+import org.raddatz.familienarchiv.person.PersonService;
+
+import org.springframework.orm.ObjectOptimisticLockingFailureException;
+
+import java.time.LocalDate;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Optional;
+import java.util.Set;
+import java.util.UUID;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.mockito.AdditionalAnswers.returnsFirstArg;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyList;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+@ExtendWith(MockitoExtension.class)
+class TimelineEventServiceTest {
+
+    @Mock TimelineEventRepository events;
+    @Mock PersonService personService;
+    @Mock DocumentService documentService;
+    @InjectMocks TimelineEventService service;
+
+    private final UUID actor = UUID.randomUUID();
+    private final UUID secondEditor = UUID.randomUUID();
+
+    /** Mirrors #774's makeEvent defaults so NOT NULL createdBy/updatedBy aren't tripped for the wrong reason. */
+    private TimelineEventRequest baseRequest() {
+        return new TimelineEventRequest(
+                "Hochzeit von Anna und Otto", EventType.PERSONAL, LocalDate.of(1914, 7, 28),
+                null, null, null, null, null, null);
+    }
+
+    private Person makePerson(UUID id) {
+        return Person.builder().id(id).firstName("Anna").lastName("Müller").build();
+    }
+
+    private Document makeDocument(UUID id) {
+        return Document.builder().id(id).title("Brief an Anna").documentDate(LocalDate.of(1914, 6, 1)).build();
+    }
+
+    /** A managed, persisted event for update/delete/get paths — version 5, distinct creator. */
+    private TimelineEvent existingEvent(UUID id, UUID creator) {
+        return TimelineEvent.builder()
+                .id(id).title("Original").type(EventType.PERSONAL).eventDate(LocalDate.of(1914, 1, 1))
+                .precision(DatePrecision.YEAR).createdBy(creator).updatedBy(creator).version(5L)
+                .build();
+    }
+
+    /** Stubs saveAndFlush to mimic Hibernate setting version=0 on insert; returns the same managed entity. */
+    private void stubFlushSetsVersion() {
+        when(events.saveAndFlush(any())).thenAnswer(inv -> {
+            TimelineEvent e = inv.getArgument(0);
+            if (e.getVersion() == null) e.setVersion(0L);
+            return e;
+        });
+    }
+
+    private TimelineEvent captureSaved() {
+        ArgumentCaptor<TimelineEvent> captor = ArgumentCaptor.forClass(TimelineEvent.class);
+        verify(events).saveAndFlush(captor.capture());
+        return captor.getValue();
+    }
+
+    // --- create ---
+
+    @Test
+    void create_persists_and_sets_createdBy_and_updatedBy_from_actorId() {
+        stubFlushSetsVersion();
+
+        TimelineEventView view = service.create(baseRequest(), actor);
+
+        TimelineEvent persisted = captureSaved();
+        assertThat(persisted.getCreatedBy()).isEqualTo(actor);
+        assertThat(persisted.getUpdatedBy()).isEqualTo(actor);
+        assertThat(view.title()).isEqualTo("Hochzeit von Anna und Otto");
+        assertThat(view.version()).isEqualTo(0L);
+    }
+
+    @Test
+    void create_defaults_precision_to_YEAR_when_omitted() {
+        stubFlushSetsVersion();
+
+        TimelineEventView view = service.create(baseRequest(), actor);
+
+        assertThat(view.precision()).isEqualTo(DatePrecision.YEAR);
+    }
+
+    @Test
+    void create_normalizes_eventDate_to_first_of_january_when_precision_is_YEAR() {
+        stubFlushSetsVersion();
+        TimelineEventRequest request = new TimelineEventRequest(
+                "Hochzeit", EventType.PERSONAL, LocalDate.of(1914, 7, 28),
+                DatePrecision.YEAR, null, null, null, null, null);
+
+        TimelineEventView view = service.create(request, actor);
+
+        assertThat(view.eventDate()).isEqualTo(LocalDate.of(1914, 1, 1));
+    }
+
+    @Test
+    void create_with_null_link_lists_yields_empty_collections_no_npe() {
+        stubFlushSetsVersion();
+
+        TimelineEventView view = service.create(baseRequest(), actor);
+
+        assertThat(view.persons()).isEmpty();
+        assertThat(view.documents()).isEmpty();
+    }
+
+    // --- RANGE invariant (both directions are separate tests; each asserts saveAndFlush never called) ---
+
+    @Test
+    void create_rejects_eventDateEnd_when_precision_is_not_RANGE() {
+        TimelineEventRequest request = new TimelineEventRequest(
+                "Krieg", EventType.HISTORICAL, LocalDate.of(1914, 1, 1),
+                DatePrecision.YEAR, LocalDate.of(1918, 1, 1), null, null, null, null);
+
+        assertThatThrownBy(() -> service.create(request, actor))
+                .isInstanceOf(DomainException.class)
+                .extracting(e -> ((DomainException) e).getCode()).isEqualTo(ErrorCode.INVALID_DATE_RANGE);
+        verify(events, never()).saveAndFlush(any());
+    }
+
+    @Test
+    void create_rejects_RANGE_with_null_eventDateEnd() {
+        TimelineEventRequest request = new TimelineEventRequest(
+                "Krieg", EventType.HISTORICAL, LocalDate.of(1914, 1, 1),
+                DatePrecision.RANGE, null, null, null, null, null);
+
+        assertThatThrownBy(() -> service.create(request, actor))
+                .isInstanceOf(DomainException.class)
+                .extracting(e -> ((DomainException) e).getCode()).isEqualTo(ErrorCode.INVALID_DATE_RANGE);
+        verify(events, never()).saveAndFlush(any());
+    }
+
+    @Test
+    void create_rejects_RANGE_with_eventDateEnd_before_eventDate() {
+        TimelineEventRequest request = new TimelineEventRequest(
+                "Krieg", EventType.HISTORICAL, LocalDate.of(1918, 11, 11),
+                DatePrecision.RANGE, LocalDate.of(1914, 7, 28), null, null, null, null); // end < start
+
+        assertThatThrownBy(() -> service.create(request, actor))
+                .isInstanceOf(DomainException.class)
+                .extracting(e -> ((DomainException) e).getCode()).isEqualTo(ErrorCode.INVALID_DATE_RANGE);
+        verify(events, never()).saveAndFlush(any());
+    }
+
+    @Test
+    void create_accepts_RANGE_with_eventDateEnd_equal_to_eventDate() {
+        stubFlushSetsVersion();
+        LocalDate sameDay = LocalDate.of(1914, 7, 28);
+        TimelineEventRequest request = new TimelineEventRequest(
+                "Eintägiges Ereignis", EventType.HISTORICAL, sameDay,
+                DatePrecision.RANGE, sameDay, null, null, null, null); // end == start is a valid closed range
+
+        TimelineEventView view = service.create(request, actor);
+
+        assertThat(view.eventDate()).isEqualTo(sameDay);
+        assertThat(view.eventDateEnd()).isEqualTo(sameDay);
+    }
+
+    // --- title-length service guard ---
+
+    @Test
+    void create_rejects_title_longer_than_255_with_TIMELINE_TITLE_TOO_LONG() {
+        String overLong = "x".repeat(256);
+        TimelineEventRequest request = new TimelineEventRequest(
+                overLong, EventType.PERSONAL, LocalDate.of(1914, 7, 28),
+                null, null, null, null, null, null);
+
+        assertThatThrownBy(() -> service.create(request, actor))
+                .isInstanceOf(DomainException.class)
+                .extracting(e -> ((DomainException) e).getCode()).isEqualTo(ErrorCode.TIMELINE_TITLE_TOO_LONG);
+        verify(events, never()).saveAndFlush(any());
+    }
+
+    // --- link resolution (fail-closed, dedupe-first) ---
+
+    @Test
+    void create_resolves_persons_and_documents() {
+        stubFlushSetsVersion();
+        UUID personId = UUID.randomUUID();
+        UUID docId = UUID.randomUUID();
+        when(personService.getAllById(anyList())).thenReturn(List.of(makePerson(personId)));
+        when(documentService.getDocumentById(docId)).thenReturn(makeDocument(docId));
+        TimelineEventRequest request = new TimelineEventRequest(
+                "Hochzeit", EventType.PERSONAL, LocalDate.of(1914, 7, 28),
+                null, null, null, null, List.of(personId), List.of(docId));
+
+        TimelineEventView view = service.create(request, actor);
+
+        assertThat(view.persons()).singleElement().satisfies(p -> assertThat(p.id()).isEqualTo(personId));
+        assertThat(view.documents()).singleElement().satisfies(d -> assertThat(d.id()).isEqualTo(docId));
+    }
+
+    @Test
+    void create_with_duplicate_personIds_resolves_to_single_link_not_404() {
+        stubFlushSetsVersion();
+        UUID personId = UUID.randomUUID();
+        when(personService.getAllById(anyList())).thenReturn(List.of(makePerson(personId)));
+        TimelineEventRequest request = new TimelineEventRequest(
+                "Hochzeit", EventType.PERSONAL, LocalDate.of(1914, 7, 28),
+                null, null, null, null, List.of(personId, personId), null);
+
+        TimelineEventView view = service.create(request, actor);
+
+        assertThat(view.persons()).hasSize(1);
+    }
+
+    @Test
+    void create_with_duplicate_documentIds_resolves_to_single_link_not_404() {
+        stubFlushSetsVersion();
+        UUID docId = UUID.randomUUID();
+        when(documentService.getDocumentById(docId)).thenReturn(makeDocument(docId));
+        TimelineEventRequest request = new TimelineEventRequest(
+                "Hochzeit", EventType.PERSONAL, LocalDate.of(1914, 7, 28),
+                null, null, null, null, null, List.of(docId, docId));
+
+        TimelineEventView view = service.create(request, actor);
+
+        assertThat(view.documents()).hasSize(1);
+    }
+
+    @Test
+    void create_rejects_unknown_personId_with_PERSON_NOT_FOUND_without_saving() {
+        UUID known = UUID.randomUUID();
+        UUID unknown = UUID.randomUUID();
+        when(personService.getAllById(anyList())).thenReturn(List.of(makePerson(known))); // one missing
+        TimelineEventRequest request = new TimelineEventRequest(
+                "Hochzeit", EventType.PERSONAL, LocalDate.of(1914, 7, 28),
+                null, null, null, null, List.of(known, unknown), null);
+
+        assertThatThrownBy(() -> service.create(request, actor))
+                .isInstanceOf(DomainException.class)
+                .extracting(e -> ((DomainException) e).getCode()).isEqualTo(ErrorCode.PERSON_NOT_FOUND);
+        verify(events, never()).saveAndFlush(any());
+    }
+
+    @Test
+    void create_rejects_unknown_documentId_with_DOCUMENT_NOT_FOUND_without_saving() {
+        UUID unknown = UUID.randomUUID();
+        when(documentService.getDocumentById(unknown))
+                .thenThrow(DomainException.notFound(ErrorCode.DOCUMENT_NOT_FOUND, "Document not found: " + unknown));
+        TimelineEventRequest request = new TimelineEventRequest(
+                "Hochzeit", EventType.PERSONAL, LocalDate.of(1914, 7, 28),
+                null, null, null, null, null, List.of(unknown));
+
+        assertThatThrownBy(() -> service.create(request, actor))
+                .isInstanceOf(DomainException.class)
+                .extracting(e -> ((DomainException) e).getCode()).isEqualTo(ErrorCode.DOCUMENT_NOT_FOUND);
+        verify(events, never()).saveAndFlush(any());
+    }
+
+    // --- update ---
+
+    @Test
+    void update_replaces_links_preserves_createdBy_and_advances_updatedBy_to_second_editor() {
+        UUID id = UUID.randomUUID();
+        UUID creator = UUID.randomUUID();
+        UUID newPersonId = UUID.randomUUID();
+        TimelineEvent existing = existingEvent(id, creator);
+        existing.getPersons().add(makePerson(UUID.randomUUID())); // pre-existing link to be replaced
+        when(events.findById(id)).thenReturn(Optional.of(existing));
+        when(events.saveAndFlush(any())).thenAnswer(returnsFirstArg());
+        when(personService.getAllById(anyList())).thenReturn(List.of(makePerson(newPersonId)));
+        TimelineEventRequest request = new TimelineEventRequest(
+                "Updated", EventType.PERSONAL, LocalDate.of(1914, 7, 28),
+                null, null, null, null, List.of(newPersonId), null);
+
+        service.update(id, request, secondEditor);
+
+        assertThat(existing.getCreatedBy()).isEqualTo(creator);
+        assertThat(existing.getUpdatedBy()).isEqualTo(secondEditor);
+        assertThat(existing.getPersons()).singleElement()
+                .satisfies(p -> assertThat(p.getId()).isEqualTo(newPersonId));
+    }
+
+    @Test
+    void update_with_empty_link_lists_clears_all_links() {
+        UUID id = UUID.randomUUID();
+        TimelineEvent existing = existingEvent(id, UUID.randomUUID());
+        existing.getPersons().add(makePerson(UUID.randomUUID()));
+        existing.getDocuments().add(makeDocument(UUID.randomUUID()));
+        when(events.findById(id)).thenReturn(Optional.of(existing));
+        when(events.saveAndFlush(any())).thenAnswer(returnsFirstArg());
+        TimelineEventRequest request = new TimelineEventRequest(
+                "Updated", EventType.PERSONAL, LocalDate.of(1914, 7, 28),
+                null, null, null, null, List.of(), List.of());
+
+        service.update(id, request, secondEditor);
+
+        assertThat(existing.getPersons()).isEmpty();
+        assertThat(existing.getDocuments()).isEmpty();
+    }
+
+    @Test
+    void update_rejects_RANGE_with_eventDateEnd_before_eventDate_without_saving() {
+        UUID id = UUID.randomUUID();
+        TimelineEvent existing = existingEvent(id, UUID.randomUUID());
+        when(events.findById(id)).thenReturn(Optional.of(existing));
+        TimelineEventRequest request = new TimelineEventRequest(
+                "Krieg", EventType.HISTORICAL, LocalDate.of(1918, 11, 11),
+                DatePrecision.RANGE, LocalDate.of(1914, 7, 28), null, null, null, null); // end < start
+
+        assertThatThrownBy(() -> service.update(id, request, secondEditor))
+                .isInstanceOf(DomainException.class)
+                .extracting(e -> ((DomainException) e).getCode()).isEqualTo(ErrorCode.INVALID_DATE_RANGE);
+        verify(events, never()).saveAndFlush(any());
+    }
+
+    @Test
+    void update_of_missing_id_throws_TIMELINE_EVENT_NOT_FOUND() {
+        UUID id = UUID.randomUUID();
+        when(events.findById(id)).thenReturn(Optional.empty());
+
+        assertThatThrownBy(() -> service.update(id, baseRequest(), actor))
+                .isInstanceOf(DomainException.class)
+                .extracting(e -> ((DomainException) e).getCode()).isEqualTo(ErrorCode.TIMELINE_EVENT_NOT_FOUND);
+    }
+
+    // --- version / optimistic lock ---
+
+    // Note: the lock control is an explicit base-version compare (requireVersionMatch), NOT
+    // event.setVersion(clientVersion) — Hibernate silently ignores a manually-set @Version on a
+    // managed entity (proven by TimelineEventServiceIntegrationTest). The saveAndFlush+catch below
+    // is retained as the native backstop for two transactions flushing concurrently.
+
+    @Test
+    void update_with_null_version_skips_the_check_and_saves_last_write_wins() {
+        UUID id = UUID.randomUUID();
+        TimelineEvent existing = existingEvent(id, UUID.randomUUID()); // version 5
+        when(events.findById(id)).thenReturn(Optional.of(existing));
+        when(events.saveAndFlush(any())).thenAnswer(returnsFirstArg());
+
+        service.update(id, baseRequest(), secondEditor); // baseRequest has null version
+
+        verify(events).saveAndFlush(existing); // no conflict despite an unknown client base
+    }
+
+    @Test
+    void update_with_in_sync_version_succeeds_and_saves() {
+        UUID id = UUID.randomUUID();
+        TimelineEvent existing = existingEvent(id, UUID.randomUUID()); // version 5
+        when(events.findById(id)).thenReturn(Optional.of(existing));
+        when(events.saveAndFlush(any())).thenAnswer(returnsFirstArg());
+        TimelineEventRequest request = new TimelineEventRequest(
+                "Updated", EventType.PERSONAL, LocalDate.of(1914, 7, 28),
+                null, null, null, 5L, null, null); // matches the loaded version
+
+        TimelineEventView view = service.update(id, request, secondEditor);
+
+        assertThat(view).isNotNull();
+        verify(events).saveAndFlush(existing);
+    }
+
+    @Test
+    void update_with_stale_version_throws_conflict_without_saving() {
+        UUID id = UUID.randomUUID();
+        TimelineEvent existing = existingEvent(id, UUID.randomUUID()); // version 5
+        when(events.findById(id)).thenReturn(Optional.of(existing));
+        TimelineEventRequest request = new TimelineEventRequest(
+                "Updated", EventType.PERSONAL, LocalDate.of(1914, 7, 28),
+                null, null, null, 2L, null, null); // stale: 2 != 5
+
+        assertThatThrownBy(() -> service.update(id, request, secondEditor))
+                .isInstanceOf(DomainException.class)
+                .extracting(e -> ((DomainException) e).getCode()).isEqualTo(ErrorCode.TIMELINE_EVENT_CONFLICT);
+        verify(events, never()).saveAndFlush(any());
+    }
+
+    @Test
+    void update_translates_concurrent_flush_lock_failure_to_TIMELINE_EVENT_CONFLICT() {
+        // Native @Version backstop: an in-sync token passes the explicit guard, but a genuinely
+        // concurrent flush makes saveAndFlush throw — it must still surface as a 409, not a 500.
+        UUID id = UUID.randomUUID();
+        TimelineEvent existing = existingEvent(id, UUID.randomUUID()); // version 5
+        when(events.findById(id)).thenReturn(Optional.of(existing));
+        when(events.saveAndFlush(any()))
+                .thenThrow(new ObjectOptimisticLockingFailureException(TimelineEvent.class, id));
+        TimelineEventRequest request = new TimelineEventRequest(
+                "Updated", EventType.PERSONAL, LocalDate.of(1914, 7, 28),
+                null, null, null, 5L, null, null); // in-sync, passes the guard
+
+        assertThatThrownBy(() -> service.update(id, request, secondEditor))
+                .isInstanceOf(DomainException.class)
+                .extracting(e -> ((DomainException) e).getCode()).isEqualTo(ErrorCode.TIMELINE_EVENT_CONFLICT);
+    }
+
+    // --- delete / getEvent ---
+
+    @Test
+    void delete_removes_existing_event() {
+        UUID id = UUID.randomUUID();
+        TimelineEvent existing = existingEvent(id, UUID.randomUUID());
+        when(events.findById(id)).thenReturn(Optional.of(existing));
+
+        service.delete(id);
+
+        verify(events).delete(existing);
+    }
+
+    @Test
+    void delete_of_missing_id_throws_TIMELINE_EVENT_NOT_FOUND() {
+        UUID id = UUID.randomUUID();
+        when(events.findById(id)).thenReturn(Optional.empty());
+
+        assertThatThrownBy(() -> service.delete(id))
+                .isInstanceOf(DomainException.class)
+                .extracting(e -> ((DomainException) e).getCode()).isEqualTo(ErrorCode.TIMELINE_EVENT_NOT_FOUND);
+    }
+
+    @Test
+    void getEvent_returns_view_for_existing_event() {
+        UUID id = UUID.randomUUID();
+        TimelineEvent existing = existingEvent(id, UUID.randomUUID());
+        when(events.findById(id)).thenReturn(Optional.of(existing));
+
+        TimelineEventView view = service.getEvent(id);
+
+        assertThat(view.id()).isEqualTo(id);
+        assertThat(view.title()).isEqualTo("Original");
+    }
+
+    @Test
+    void getEvent_of_missing_id_throws_TIMELINE_EVENT_NOT_FOUND() {
+        UUID id = UUID.randomUUID();
+        when(events.findById(id)).thenReturn(Optional.empty());
+
+        assertThatThrownBy(() -> service.getEvent(id))
+                .isInstanceOf(DomainException.class)
+                .extracting(e -> ((DomainException) e).getCode()).isEqualTo(ErrorCode.TIMELINE_EVENT_NOT_FOUND);
+    }
+}

backend/src/test/java/org/raddatz/familienarchiv/timeline/TimelineServiceIntegrationTest.java

@@ -0,0 +1,105 @@
+package org.raddatz.familienarchiv.timeline;
+
+import jakarta.persistence.EntityManager;
+import jakarta.persistence.PersistenceContext;
+import org.junit.jupiter.api.Test;
+import org.raddatz.familienarchiv.PostgresContainerConfig;
+import org.raddatz.familienarchiv.document.DatePrecision;
+import org.raddatz.familienarchiv.person.Person;
+import org.raddatz.familienarchiv.person.PersonRepository;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.context.annotation.Import;
+import org.springframework.test.context.ActiveProfiles;
+import org.springframework.test.context.bean.override.mockito.MockitoBean;
+import org.springframework.transaction.annotation.Transactional;
+import software.amazon.awssdk.services.s3.S3Client;
+
+import java.time.LocalDate;
+import java.util.List;
+import java.util.UUID;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Integration tests for {@link TimelineService} and {@link PersonRepository#findByGeneration}
+ * against real Postgres. Verifies that assembled output reflects persisted curated events and
+ * that the generation query handles null-generation rows correctly.
+ */
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.NONE)
+@ActiveProfiles("test")
+@Import(PostgresContainerConfig.class)
+@Transactional
+class TimelineServiceIntegrationTest {
+
+    @MockitoBean S3Client s3Client;
+
+    @Autowired TimelineService timelineService;
+    @Autowired TimelineEventRepository timelineEventRepository;
+    @Autowired PersonRepository personRepository;
+
+    @PersistenceContext EntityManager em;
+
+    // ─── PersonRepository.findByGeneration ────────────────────────────────────
+
+    @Test
+    void findByGeneration_returns_matching_persons() {
+        personRepository.save(Person.builder().lastName("Gen2A").generation(2).build());
+        personRepository.save(Person.builder().lastName("Gen2B").generation(2).build());
+        personRepository.save(Person.builder().lastName("Gen3").generation(3).build());
+        em.flush();
+
+        List<Person> result = personRepository.findByGeneration(2);
+
+        assertThat(result).extracting(Person::getLastName)
+                .containsExactlyInAnyOrder("Gen2A", "Gen2B");
+    }
+
+    @Test
+    void findByGeneration_returns_empty_list_not_npe_when_no_match() {
+        personRepository.save(Person.builder().lastName("Gen1").generation(1).build());
+        em.flush();
+
+        List<Person> result = personRepository.findByGeneration(99);
+
+        assertThat(result).isNotNull().isEmpty();
+    }
+
+    @Test
+    void findByGeneration_does_not_return_null_generation_persons() {
+        personRepository.save(Person.builder().lastName("NullGen").build()); // generation stays null
+        em.flush();
+
+        List<Person> result = personRepository.findByGeneration(1);
+
+        assertThat(result).extracting(Person::getLastName).doesNotContain("NullGen");
+    }
+
+    // ─── TimelineService.assemble end-to-end ─────────────────────────────────
+
+    @Test
+    void assemble_includes_persisted_curated_event_in_correct_year_band() {
+        UUID actorId = UUID.randomUUID();
+        TimelineEvent event = timelineEventRepository.save(TimelineEvent.builder()
+                .title("Sarajevo")
+                .type(EventType.HISTORICAL)
+                .eventDate(LocalDate.of(1914, 6, 28))
+                .precision(DatePrecision.DAY)
+                .createdBy(actorId)
+                .updatedBy(actorId)
+                .build());
+        em.flush();
+        em.clear();
+
+        TimelineDTO result = timelineService.assemble(new TimelineFilter(null, null, null, null, null));
+
+        assertThat(result.years()).anySatisfy(y -> {
+            assertThat(y.year()).isEqualTo(1914);
+            assertThat(y.entries()).anySatisfy(e -> {
+                assertThat(e.title()).isEqualTo("Sarajevo");
+                assertThat(e.kind()).isEqualTo(Kind.EVENT);
+                assertThat(e.eventId()).isEqualTo(event.getId());
+            });
+        });
+    }
+}

backend/src/test/java/org/raddatz/familienarchiv/timeline/TimelineServiceLazyLoadTest.java

@@ -0,0 +1,72 @@
+package org.raddatz.familienarchiv.timeline;
+
+import org.junit.jupiter.api.Test;
+import org.raddatz.familienarchiv.PostgresContainerConfig;
+import org.raddatz.familienarchiv.document.DatePrecision;
+import org.raddatz.familienarchiv.person.Person;
+import org.raddatz.familienarchiv.person.PersonRepository;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.context.annotation.Import;
+import org.springframework.test.context.ActiveProfiles;
+import org.springframework.test.context.bean.override.mockito.MockitoBean;
+import org.springframework.transaction.support.TransactionTemplate;
+import software.amazon.awssdk.services.s3.S3Client;
+
+import java.time.LocalDate;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.UUID;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+
+/**
+ * Verifies that {@link TimelineService#assemble} does not throw
+ * {@link org.hibernate.LazyInitializationException} when events have linked persons.
+ *
+ * <p>No class-level {@code @Transactional} — each test method runs without an outer
+ * transaction, matching production behaviour (controller has no {@code @Transactional}).
+ * If {@code assemble()} lacks {@code @Transactional(readOnly=true)}, accessing
+ * {@code ev.getPersons()} on detached entities throws LazyInitializationException.
+ */
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.NONE)
+@ActiveProfiles("test")
+@Import(PostgresContainerConfig.class)
+class TimelineServiceLazyLoadTest {
+
+    @MockitoBean
+    S3Client s3Client;
+
+    @Autowired
+    TransactionTemplate transactionTemplate;
+
+    @Autowired
+    TimelineService timelineService;
+
+    @Autowired
+    TimelineEventRepository timelineEventRepository;
+
+    @Autowired
+    PersonRepository personRepository;
+
+    @Test
+    void assemble_does_not_throw_when_event_has_linked_persons() {
+        UUID actorId = UUID.randomUUID();
+        // Commit outside any test-managed transaction so entities are detached on return
+        transactionTemplate.execute(status -> {
+            Person person = personRepository.save(Person.builder().lastName("Müller").build());
+            timelineEventRepository.save(TimelineEvent.builder()
+                    .title("Linked event")
+                    .type(EventType.HISTORICAL)
+                    .eventDate(LocalDate.of(1914, 7, 28))
+                    .precision(DatePrecision.DAY)
+                    .createdBy(actorId)
+                    .updatedBy(actorId)
+                    .persons(new HashSet<>(Set.of(person)))
+                    .build());
+            return null;
+        });
+
+        assertDoesNotThrow(() -> timelineService.assemble(new TimelineFilter(null, null, null, null, null)));
+    }
+}

backend/src/test/java/org/raddatz/familienarchiv/timeline/TimelineServiceTest.java

@@ -0,0 +1,452 @@
+package org.raddatz.familienarchiv.timeline;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.raddatz.familienarchiv.document.DatePrecision;
+import org.raddatz.familienarchiv.document.Document;
+import org.raddatz.familienarchiv.document.DocumentService;
+import org.raddatz.familienarchiv.exception.DomainException;
+import org.raddatz.familienarchiv.person.Person;
+import org.raddatz.familienarchiv.person.PersonService;
+
+import java.time.LocalDate;
+import java.util.List;
+import java.util.Set;
+import java.util.UUID;
+
+import static org.assertj.core.api.Assertions.*;
+import static org.mockito.Mockito.*;
+
+@ExtendWith(MockitoExtension.class)
+class TimelineServiceTest {
+
+    @Mock TimelineEventRepository eventRepository;
+    @Mock TimelineEventService timelineEventService;
+    @Mock DocumentService documentService;
+    @Mock PersonService personService;
+
+    @InjectMocks TimelineService timelineService;
+
+    // ─── WITHIN_BAND_ORDER standalone tests (REQ-002) ────────────────────────
+
+    @Test
+    void within_band_order_day_precision_sorts_before_year() {
+        var dayEntry = letter(LocalDate.of(1914, 7, 28), DatePrecision.DAY, "B-brief");
+        var yearEntry = letter(LocalDate.of(1914, 1, 1), DatePrecision.YEAR, "A-brief");
+
+        var sorted = List.of(yearEntry, dayEntry).stream()
+                .sorted(TimelineService.WITHIN_BAND_ORDER)
+                .toList();
+
+        assertThat(sorted).containsExactly(dayEntry, yearEntry);
+    }
+
+    @Test
+    void within_band_order_same_precision_and_date_sorts_alphabetically() {
+        var entryZ = letter(LocalDate.of(1914, 7, 28), DatePrecision.DAY, "Zimmer");
+        var entryA = letter(LocalDate.of(1914, 7, 28), DatePrecision.DAY, "Adler");
+
+        var sorted = List.of(entryZ, entryA).stream()
+                .sorted(TimelineService.WITHIN_BAND_ORDER)
+                .toList();
+
+        assertThat(sorted).containsExactly(entryA, entryZ);
+    }
+
+    @Test
+    void within_band_order_same_title_uses_document_id_as_tiebreak() {
+        UUID id1 = UUID.fromString("00000000-0000-0000-0000-000000000001");
+        UUID id2 = UUID.fromString("00000000-0000-0000-0000-000000000002");
+        var e1 = new TimelineEntryDTO(Kind.LETTER, DatePrecision.DAY, false, "", "",
+                LocalDate.of(1914, 7, 28), null, "Same Title", null, null, id1, List.of(), null);
+        var e2 = new TimelineEntryDTO(Kind.LETTER, DatePrecision.DAY, false, "", "",
+                LocalDate.of(1914, 7, 28), null, "Same Title", null, null, id2, List.of(), null);
+
+        var sorted = List.of(e2, e1).stream()
+                .sorted(TimelineService.WITHIN_BAND_ORDER)
+                .toList();
+
+        assertThat(sorted.get(0).documentId()).isEqualTo(id1);
+    }
+
+    // ─── Assembly tests (issue-spec order) ──────────────────────────────────
+
+    @Test
+    void test1_empty_archive_returns_empty_dto() {
+        // REQ-013, REQ-007
+        when(eventRepository.findAll()).thenReturn(List.of());
+        when(timelineEventService.assembleDerivedEvents()).thenReturn(List.of());
+        when(documentService.getAllForTimeline()).thenReturn(List.of());
+
+        TimelineDTO result = timelineService.assemble(noFilters());
+
+        assertThat(result.years()).isEmpty();
+        assertThat(result.undated()).isEmpty();
+    }
+
+    @Test
+    void test2_one_year_letter_returns_one_year_band() {
+        // REQ-007
+        var doc = docWithDate(LocalDate.of(1914, 1, 1), DatePrecision.YEAR);
+        when(eventRepository.findAll()).thenReturn(List.of());
+        when(timelineEventService.assembleDerivedEvents()).thenReturn(List.of());
+        when(documentService.getAllForTimeline()).thenReturn(List.of(doc));
+
+        TimelineDTO result = timelineService.assemble(noFilters());
+
+        assertThat(result.years()).hasSize(1);
+        assertThat(result.years().get(0).year()).isEqualTo(1914);
+        assertThat(result.years().get(0).entries()).hasSize(1);
+        assertThat(result.years().get(0).entries().get(0).kind()).isEqualTo(Kind.LETTER);
+        assertThat(result.undated()).isEmpty();
+    }
+
+    @Test
+    void test3a_null_date_letter_goes_to_undated() {
+        // REQ-003
+        var doc = Document.builder().id(UUID.randomUUID()).title("Brief")
+                .metaDatePrecision(DatePrecision.YEAR).build(); // documentDate stays null
+        when(eventRepository.findAll()).thenReturn(List.of());
+        when(timelineEventService.assembleDerivedEvents()).thenReturn(List.of());
+        when(documentService.getAllForTimeline()).thenReturn(List.of(doc));
+
+        TimelineDTO result = timelineService.assemble(noFilters());
+
+        assertThat(result.years()).isEmpty();
+        assertThat(result.undated()).hasSize(1);
+    }
+
+    @Test
+    void test3b_unknown_precision_letter_goes_to_undated() {
+        // REQ-003
+        var doc = docWithDate(LocalDate.of(1914, 1, 1), DatePrecision.UNKNOWN);
+        when(eventRepository.findAll()).thenReturn(List.of());
+        when(timelineEventService.assembleDerivedEvents()).thenReturn(List.of());
+        when(documentService.getAllForTimeline()).thenReturn(List.of(doc));
+
+        TimelineDTO result = timelineService.assemble(noFilters());
+
+        assertThat(result.years()).isEmpty();
+        assertThat(result.undated()).hasSize(1);
+    }
+
+    @Test
+    void test4_letter_with_null_sender_and_null_senderText_produces_empty_names() {
+        // REQ-005
+        var doc = Document.builder().id(UUID.randomUUID()).title("Brief")
+                .metaDatePrecision(DatePrecision.YEAR)
+                .documentDate(LocalDate.of(1914, 1, 1))
+                .build(); // no sender, no senderText, no receivers, no receiverText
+        when(eventRepository.findAll()).thenReturn(List.of());
+        when(timelineEventService.assembleDerivedEvents()).thenReturn(List.of());
+        when(documentService.getAllForTimeline()).thenReturn(List.of(doc));
+
+        TimelineDTO result = timelineService.assemble(noFilters());
+
+        var entry = result.years().get(0).entries().get(0);
+        assertThat(entry.senderName()).isEqualTo("");
+        assertThat(entry.receiverName()).isEqualTo("");
+    }
+
+    @Test
+    void test5_day_precision_sorts_before_year_in_same_year_band() {
+        // REQ-002
+        var dayLetter = docWithDate(LocalDate.of(1914, 7, 28), DatePrecision.DAY, "B-brief");
+        var yearLetter = docWithDate(LocalDate.of(1914, 1, 1), DatePrecision.YEAR, "A-brief");
+        when(eventRepository.findAll()).thenReturn(List.of());
+        when(timelineEventService.assembleDerivedEvents()).thenReturn(List.of());
+        when(documentService.getAllForTimeline()).thenReturn(List.of(yearLetter, dayLetter));
+
+        TimelineDTO result = timelineService.assemble(noFilters());
+
+        var entries = result.years().get(0).entries();
+        assertThat(entries).hasSize(2);
+        assertThat(entries.get(0).precision()).isEqualTo(DatePrecision.DAY);
+        assertThat(entries.get(1).precision()).isEqualTo(DatePrecision.YEAR);
+    }
+
+    @Test
+    void test6_same_precision_same_date_sorted_alphabetically_by_title() {
+        // REQ-002
+        var letterZ = docWithDate(LocalDate.of(1914, 7, 28), DatePrecision.DAY, "Zimmer");
+        var letterA = docWithDate(LocalDate.of(1914, 7, 28), DatePrecision.DAY, "Adler");
+        when(eventRepository.findAll()).thenReturn(List.of());
+        when(timelineEventService.assembleDerivedEvents()).thenReturn(List.of());
+        when(documentService.getAllForTimeline()).thenReturn(List.of(letterZ, letterA));
+
+        TimelineDTO result = timelineService.assemble(noFilters());
+
+        var entries = result.years().get(0).entries();
+        assertThat(entries).hasSize(2);
+        assertThat(entries.get(0).title()).isEqualTo("Adler");
+        assertThat(entries.get(1).title()).isEqualTo("Zimmer");
+    }
+
+    @Test
+    void test7a_range_event_placed_only_in_start_year_band() {
+        // REQ-004
+        var rangeEvent = event("WW1", EventType.HISTORICAL,
+                LocalDate.of(1914, 7, 28), DatePrecision.RANGE, LocalDate.of(1918, 11, 11));
+        when(eventRepository.findAll()).thenReturn(List.of(rangeEvent));
+        when(timelineEventService.assembleDerivedEvents()).thenReturn(List.of());
+        when(documentService.getAllForTimeline()).thenReturn(List.of());
+
+        TimelineDTO result = timelineService.assemble(noFilters());
+
+        assertThat(result.years()).hasSize(1);
+        assertThat(result.years().get(0).year()).isEqualTo(1914);
+        assertThat(result.years().stream().noneMatch(y -> y.year() == 1918)).isTrue();
+    }
+
+    @Test
+    void test7b_range_event_with_null_eventDateEnd_does_not_crash() {
+        // REQ-004
+        var rangeEvent = event("Offener Zeitraum", EventType.PERSONAL,
+                LocalDate.of(1914, 1, 1), DatePrecision.RANGE, null);
+        when(eventRepository.findAll()).thenReturn(List.of(rangeEvent));
+        when(timelineEventService.assembleDerivedEvents()).thenReturn(List.of());
+        when(documentService.getAllForTimeline()).thenReturn(List.of());
+
+        assertThatCode(() -> timelineService.assemble(noFilters())).doesNotThrowAnyException();
+    }
+
+    @Test
+    void test8_range_event_excluded_when_start_year_before_fromYear() {
+        // REQ-004
+        var rangeEvent = event("WW1", EventType.HISTORICAL,
+                LocalDate.of(1914, 7, 28), DatePrecision.RANGE, LocalDate.of(1918, 11, 11));
+        when(eventRepository.findAll()).thenReturn(List.of(rangeEvent));
+        when(timelineEventService.assembleDerivedEvents()).thenReturn(List.of());
+        when(documentService.getAllForTimeline()).thenReturn(List.of());
+
+        // fromYear=1915 → start year 1914 is outside → excluded
+        TimelineDTO result = timelineService.assemble(new TimelineFilter(null, null, null, 1915, null));
+
+        assertThat(result.years()).isEmpty();
+    }
+
+    @Test
+    void test9a_type_filter_does_not_exclude_letters_but_excludes_wrong_type_events() {
+        // REQ-009
+        var doc = docWithDate(LocalDate.of(1914, 1, 1), DatePrecision.YEAR, "Brief");
+        var historicalEvent = event("Sarajevo", EventType.HISTORICAL,
+                LocalDate.of(1914, 6, 28), DatePrecision.DAY, null);
+        var personalEvent = event("Geburt", EventType.PERSONAL,
+                LocalDate.of(1914, 8, 1), DatePrecision.DAY, null);
+        when(eventRepository.findAll()).thenReturn(List.of(historicalEvent, personalEvent));
+        when(timelineEventService.assembleDerivedEvents()).thenReturn(List.of());
+        when(documentService.getAllForTimeline()).thenReturn(List.of(doc));
+
+        // filter: only HISTORICAL events
+        TimelineDTO result = timelineService.assemble(new TimelineFilter(null, null, EventType.HISTORICAL, null, null));
+
+        long letters = result.years().stream().flatMap(y -> y.entries().stream())
+                .filter(e -> e.kind() == Kind.LETTER).count();
+        long personalEvents = result.years().stream().flatMap(y -> y.entries().stream())
+                .filter(e -> e.kind() == Kind.EVENT && e.type() == EventType.PERSONAL).count();
+        assertThat(letters).isEqualTo(1);
+        assertThat(personalEvents).isEqualTo(0);
+    }
+
+    @Test
+    void test9b_generation_filter_includes_letter_when_sender_matches_generation() {
+        // REQ-010
+        var sender = Person.builder().id(UUID.randomUUID())
+                .lastName("Mustermann").firstName("Max").generation(2).build();
+        var included = Document.builder().id(UUID.randomUUID()).title("Treffer")
+                .metaDatePrecision(DatePrecision.YEAR).documentDate(LocalDate.of(1914, 1, 1))
+                .sender(sender).build();
+        var excluded = docWithDate(LocalDate.of(1914, 1, 1), DatePrecision.YEAR, "Kein Treffer"); // no sender
+        when(eventRepository.findAll()).thenReturn(List.of());
+        when(timelineEventService.assembleDerivedEvents()).thenReturn(List.of());
+        when(documentService.getAllForTimeline()).thenReturn(List.of(included, excluded));
+        when(personService.getPersonsByGeneration(2)).thenReturn(List.of(sender));
+
+        TimelineDTO result = timelineService.assemble(new TimelineFilter(null, 2, null, null, null));
+
+        assertThat(result.years()).hasSize(1);
+        assertThat(result.years().get(0).entries()).hasSize(1);
+        assertThat(result.years().get(0).entries().get(0).title()).isEqualTo("Treffer");
+    }
+
+    @Test
+    void test9c_fromYear_toYear_inclusive_single_year_window() {
+        // REQ-011
+        var before = docWithDate(LocalDate.of(1913, 12, 31), DatePrecision.YEAR, "Vorher");
+        var inYear = docWithDate(LocalDate.of(1914, 6, 1), DatePrecision.MONTH, "Im Jahr");
+        var after = docWithDate(LocalDate.of(1915, 1, 1), DatePrecision.YEAR, "Nachher");
+        when(eventRepository.findAll()).thenReturn(List.of());
+        when(timelineEventService.assembleDerivedEvents()).thenReturn(List.of());
+        when(documentService.getAllForTimeline()).thenReturn(List.of(before, inYear, after));
+
+        TimelineDTO result = timelineService.assemble(new TimelineFilter(null, null, null, 1914, 1914));
+
+        assertThat(result.years()).hasSize(1);
+        assertThat(result.years().get(0).year()).isEqualTo(1914);
+        assertThat(result.years().get(0).entries().get(0).title()).isEqualTo("Im Jahr");
+    }
+
+    @Test
+    void test10_adversarial_and_logic_neither_event_passes_both_filters() {
+        // REQ-012 — type AND year must both pass
+        var wrongType = event("Personal", EventType.PERSONAL,
+                LocalDate.of(1914, 1, 1), DatePrecision.YEAR, null);
+        var wrongYear = event("Historical outside", EventType.HISTORICAL,
+                LocalDate.of(1920, 1, 1), DatePrecision.YEAR, null);
+        when(eventRepository.findAll()).thenReturn(List.of(wrongType, wrongYear));
+        when(timelineEventService.assembleDerivedEvents()).thenReturn(List.of());
+        when(documentService.getAllForTimeline()).thenReturn(List.of());
+
+        TimelineDTO result = timelineService.assemble(new TimelineFilter(null, null, EventType.HISTORICAL, 1914, 1914));
+
+        assertThat(result.years()).isEmpty();
+        assertThat(result.undated()).isEmpty();
+    }
+
+    @Test
+    void test11_personId_scoping_deduplicates_letter_appearing_as_sender_and_receiver() {
+        // REQ-008
+        UUID personId = UUID.randomUUID();
+        var person = Person.builder().id(personId).lastName("Mustermann").build();
+        var doc = Document.builder().id(UUID.randomUUID()).title("Brief")
+                .metaDatePrecision(DatePrecision.YEAR).documentDate(LocalDate.of(1914, 1, 1))
+                .sender(person)
+                .receivers(Set.of(person))
+                .build();
+        when(personService.getById(personId)).thenReturn(person);
+        when(eventRepository.findAll()).thenReturn(List.of());
+        when(timelineEventService.assembleDerivedEvents()).thenReturn(List.of());
+        when(documentService.getDocumentsBySender(personId)).thenReturn(List.of(doc));
+        when(documentService.getDocumentsByReceiver(personId)).thenReturn(List.of(doc));
+
+        TimelineDTO result = timelineService.assemble(new TimelineFilter(personId, null, null, null, null));
+
+        long total = result.years().stream().mapToLong(y -> y.entries().size()).sum()
+                + result.undated().size();
+        assertThat(total).isEqualTo(1);
+    }
+
+    @Test
+    void test12_personId_plus_generation_filter_returns_empty_when_generations_do_not_match() {
+        // REQ-012
+        UUID personId = UUID.randomUUID();
+        var person = Person.builder().id(personId).lastName("Mustermann").generation(1).build();
+        var doc = Document.builder().id(UUID.randomUUID()).title("Brief")
+                .metaDatePrecision(DatePrecision.YEAR).documentDate(LocalDate.of(1914, 1, 1))
+                .sender(person).build();
+        var gen2person = Person.builder().id(UUID.randomUUID()).lastName("Schmidt").generation(2).build();
+        when(personService.getById(personId)).thenReturn(person);
+        when(eventRepository.findAll()).thenReturn(List.of());
+        when(timelineEventService.assembleDerivedEvents()).thenReturn(List.of());
+        when(documentService.getDocumentsBySender(personId)).thenReturn(List.of(doc));
+        when(documentService.getDocumentsByReceiver(personId)).thenReturn(List.of());
+        when(personService.getPersonsByGeneration(2)).thenReturn(List.of(gen2person)); // person not in gen2
+
+        TimelineDTO result = timelineService.assemble(new TimelineFilter(personId, 2, null, null, null));
+
+        assertThat(result.years()).isEmpty();
+        assertThat(result.undated()).isEmpty();
+    }
+
+    @Test
+    void test13_null_generation_sender_not_returned_by_generation_filter() {
+        // REQ-020 — both sender and receiver have null generation → excluded
+        var nullGenSender = Person.builder().id(UUID.randomUUID()).lastName("Sender").build(); // generation = null
+        var doc = Document.builder().id(UUID.randomUUID()).title("Brief")
+                .metaDatePrecision(DatePrecision.YEAR).documentDate(LocalDate.of(1914, 1, 1))
+                .sender(nullGenSender).build();
+        when(eventRepository.findAll()).thenReturn(List.of());
+        when(timelineEventService.assembleDerivedEvents()).thenReturn(List.of());
+        when(documentService.getAllForTimeline()).thenReturn(List.of(doc));
+        when(personService.getPersonsByGeneration(1)).thenReturn(List.of()); // nobody in generation 1
+
+        TimelineDTO result = timelineService.assemble(new TimelineFilter(null, 1, null, null, null));
+
+        assertThat(result.years()).isEmpty();
+        assertThat(result.undated()).isEmpty();
+    }
+
+    @Test
+    void test14_year_band_contains_only_event_when_no_letters_in_that_year() {
+        var ev = event("Ausbruch", EventType.HISTORICAL, LocalDate.of(1914, 7, 28), DatePrecision.DAY, null);
+        when(eventRepository.findAll()).thenReturn(List.of(ev));
+        when(timelineEventService.assembleDerivedEvents()).thenReturn(List.of());
+        when(documentService.getAllForTimeline()).thenReturn(List.of());
+
+        TimelineDTO result = timelineService.assemble(noFilters());
+
+        assertThat(result.years()).hasSize(1);
+        assertThat(result.years().get(0).entries()).hasSize(1);
+        assertThat(result.years().get(0).entries().get(0).kind()).isEqualTo(Kind.EVENT);
+    }
+
+    @Test
+    void test15_range_event_start_year_equal_to_fromYear_is_included() {
+        // REQ-004 — inclusive lower bound
+        var rangeEvent = event("WW1", EventType.HISTORICAL,
+                LocalDate.of(1914, 7, 28), DatePrecision.RANGE, LocalDate.of(1918, 11, 11));
+        when(eventRepository.findAll()).thenReturn(List.of(rangeEvent));
+        when(timelineEventService.assembleDerivedEvents()).thenReturn(List.of());
+        when(documentService.getAllForTimeline()).thenReturn(List.of());
+
+        TimelineDTO result = timelineService.assemble(new TimelineFilter(null, null, null, 1914, null));
+
+        assertThat(result.years()).hasSize(1);
+        assertThat(result.years().get(0).year()).isEqualTo(1914);
+    }
+
+    @Test
+    void test16_fromYear_without_toYear_returns_all_items_from_that_year_onwards() {
+        // REQ-011
+        var old = docWithDate(LocalDate.of(1919, 12, 31), DatePrecision.YEAR, "Alt");
+        var first = docWithDate(LocalDate.of(1920, 1, 1), DatePrecision.YEAR, "Erst");
+        var newer = docWithDate(LocalDate.of(1921, 6, 1), DatePrecision.YEAR, "Newer");
+        when(eventRepository.findAll()).thenReturn(List.of());
+        when(timelineEventService.assembleDerivedEvents()).thenReturn(List.of());
+        when(documentService.getAllForTimeline()).thenReturn(List.of(old, first, newer));
+
+        TimelineDTO result = timelineService.assemble(new TimelineFilter(null, null, null, 1920, null));
+
+        assertThat(result.years()).hasSize(2);
+        assertThat(result.years().stream().noneMatch(y -> y.year() == 1919)).isTrue();
+    }
+
+    @Test
+    void fromYear_greater_than_toYear_throws_bad_request() {
+        // REQ-016 (service-layer guard)
+        assertThatThrownBy(() -> timelineService.assemble(new TimelineFilter(null, null, null, 1920, 1914)))
+                .isInstanceOf(DomainException.class);
+    }
+
+    // ─── Helpers ─────────────────────────────────────────────────────────────
+
+    private static TimelineFilter noFilters() {
+        return new TimelineFilter(null, null, null, null, null);
+    }
+
+    private static TimelineEntryDTO letter(LocalDate date, DatePrecision precision, String title) {
+        return new TimelineEntryDTO(Kind.LETTER, precision, false, "", "",
+                date, null, title, null, null, UUID.randomUUID(), List.of(), null);
+    }
+
+    private static Document docWithDate(LocalDate date, DatePrecision precision) {
+        return Document.builder().id(UUID.randomUUID()).title("Brief")
+                .metaDatePrecision(precision).documentDate(date).build();
+    }
+
+    private static Document docWithDate(LocalDate date, DatePrecision precision, String title) {
+        return Document.builder().id(UUID.randomUUID()).title(title)
+                .metaDatePrecision(precision).documentDate(date).build();
+    }
+
+    private static TimelineEvent event(String title, EventType type, LocalDate date,
+                                       DatePrecision precision, LocalDate endDate) {
+        return TimelineEvent.builder().id(UUID.randomUUID())
+                .title(title).type(type)
+                .eventDate(date).precision(precision).eventDateEnd(endDate)
+                .build();
+    }
+}

docs/ARCHITECTURE.md

@@ -61,7 +61,7 @@ Members of the cross-cutting layer have no entity of their own, no user-facing C
 | `audit` | Append-only event store (`audit_log`) for all domain mutations. Feeds the activity feed and Family Pulse dashboard. | Consumed by 5+ domains; no user-facing CRUD of its own |
 | `config` | Infrastructure bean definitions: `MinioConfig`, `AsyncConfig`, `WebConfig` | Framework infra; no business logic |
 | `dashboard` | Stats aggregation for the admin dashboard and Family Pulse widget | Aggregates from 3+ domains; no owned entities |
-| `exception` | `DomainException`, `ErrorCode` enum, `GlobalExceptionHandler` | Framework infra; consumed by every controller and service. Adding a new `ErrorCode` requires matching updates in `frontend/src/lib/shared/errors.ts` and all three `messages/*.json` locale files. Current security-related codes: `CSRF_TOKEN_MISSING` (403 on mutating request without valid `X-XSRF-TOKEN` header), `TOO_MANY_LOGIN_ATTEMPTS` (429 when login rate limit exceeded). Journey/geschichte domain codes: `JOURNEY_NOTE_TOO_LONG`, `JOURNEY_DOCUMENT_ALREADY_ADDED`, `GESCHICHTE_TYPE_IMMUTABLE`, `GESCHICHTE_TITLE_TOO_LONG`, `GESCHICHTE_INTRO_TOO_LONG`. |
+| `exception` | `DomainException`, `ErrorCode` enum, `GlobalExceptionHandler` | Framework infra; consumed by every controller and service. Adding a new `ErrorCode` requires matching updates in `frontend/src/lib/shared/errors.ts` and all three `messages/*.json` locale files. Current security-related codes: `CSRF_TOKEN_MISSING` (403 on mutating request without valid `X-XSRF-TOKEN` header), `TOO_MANY_LOGIN_ATTEMPTS` (429 when login rate limit exceeded). Journey/geschichte domain codes: `JOURNEY_NOTE_TOO_LONG`, `JOURNEY_DOCUMENT_ALREADY_ADDED`, `GESCHICHTE_TYPE_IMMUTABLE`, `GESCHICHTE_TITLE_TOO_LONG`, `GESCHICHTE_INTRO_TOO_LONG`. Timeline domain codes: `TIMELINE_EVENT_NOT_FOUND`, `TIMELINE_EVENT_CONFLICT`, `TIMELINE_TITLE_TOO_LONG`, plus a generic `CONFLICT` (409 optimistic-lock backstop). |
 | `filestorage` | `FileService` — MinIO/S3 upload, download, presigned-URL generation | Generic service; consumed by `document` and `ocr` |
 | `importing` | `CanonicalImportOrchestrator` — async canonical import running four idempotent loaders (`TagTreeImporter` → `PersonRegisterImporter` → `PersonTreeImporter` → `DocumentImporter`) over the normalizer's committed canonical artifacts (`canonical-*.xlsx` + `canonical-persons-tree.json`) | Orchestrates across `person`, `tag`, `document` |
 | `security` | `SecurityConfig`, `Permission` enum, `@RequirePermission` annotation, `PermissionAspect` (AOP) | Framework infra; enforced globally across all controllers |

docs/GLOSSARY.md

@@ -168,7 +168,18 @@ _Not to be confused with a document item's optional note_ — a document item's
 
 **EventType** (`EventType`) `[user-facing]` — the kind of a `TimelineEvent`: `PERSONAL` (a family event, rendered with the family accent) or `HISTORICAL` (world/historical context, rendered with a muted world accent). The string value names are a stable frontend styling contract — renaming requires a coordinated frontend change (ADR-040).
 
-**Zeitstrahl** `[user-facing]` — the family timeline view, rendering curated `TimelineEvent`s (and, in later issues, derived life-events) chronologically. The milestone home of the `timeline` domain.
+**Zeitstrahl** `[user-facing]` — the family timeline view, rendering curated `TimelineEvent`s and derived life-events chronologically. The milestone home of the `timeline` domain.
+
+**Lebensweg** `[user-facing]` — the per-person variant of the *Zeitstrahl*: the same `TimelineView` component, scoped to a single person via a `personId` prop, rendering that person's life-events, events, and letters as a left-anchored rail. The global Zeitstrahl is the `personId`-undefined case of the same component (issue #10 wires the per-person rail; the prop seam ships with the global view).
+
+**derived event** — a timeline entry computed on-read from curated `Person` or `PersonRelationship` data, never persisted. Carried as a `TimelineEntryDTO` with `derived=true` and a non-null `DerivedEventType`. Three subtypes: Geburt (birth, from `Person.birthDate`), Tod (death, from `Person.deathDate`), Heirat (marriage, from a `SPOUSE_OF` `PersonRelationship` edge). Callers of `assembleDerivedEvents()` are responsible for enforcing `READ_ALL` authorization before invoking it (ADR-043).
+_Not to be confused with a `TimelineEvent`_ — a `TimelineEvent` is a curated record authored by a human and stored in `timeline_events`; a derived event is computed on-the-fly and never written to the database.
+
+**DerivedEventType** (`DerivedEventType`) `[internal]` — enum with three values: `BIRTH`, `DEATH`, `MARRIAGE`. Carried on `TimelineEntryDTO.derivedType`; `null` on curated-event entries exposed through the same DTO.
+
+**derivedType** (`TimelineEntryDTO.derivedType`) `[internal]` — the `DerivedEventType` field distinguishing a derived Geburt/Tod/Heirat event from a curated one. Always non-null on derived events; `null` on curated events.
+
+**assembleDerivedEvents()** (`TimelineEventService.assembleDerivedEvents()`) `[internal]` — the public `@Transactional(readOnly=true)` method that computes all derived events in one call: one batch fetch of family-member `Person`s via `PersonService.findAllFamilyMembers()` and one batch fetch of `SPOUSE_OF` edges via `RelationshipService.findAllSpouseEdges()`. Result is never persisted. Synthetic ids produced by this method (`birth:{uuid}`, `death:{uuid}`, `marriage:{uuid}`) are structurally non-UUID and must be rejected by any write endpoint. See ADR-043.
 
 **Notification** (`Notification`) — an in-app message delivered to an `AppUser`. No email or SMS delivery exists today. Delivered via Server-Sent Events (`SseEmitterRegistry`) and persisted in the `notifications` table.
 

docs/adr/042-sdd-adoption.md

@@ -0,0 +1,94 @@
+# ADR-042 — Adopt Spec-Driven Development (SDD)
+
+**Status:** Accepted
+**Date:** 2026-06-13
+**Issue:** SDD integration (docs/sdd-integration branch)
+
+> This is the "ADR-000" the SDD scaffold refers to, numbered 042 to fit the existing archive
+> sequence (041 was taken by the Renovate runner-setup ADR merged in parallel). See
+> [`.specify/adrs/README.md`](../../.specify/adrs/README.md).
+
+## Context
+
+The project already runs a lightweight, multi-persona review loop: feature work is tracked
+as dense Gitea issues, and the `review-issue` / `review-pr` / `deliver-issue` skills dispatch
+the character personas in `.claude/personas/` (requirements engineer, developer, security,
+devops, ui, architect, tester) to comment on issues and PRs. `COLLABORATING.md` already
+mandates a Research → Plan → Implement → Validate cycle, red/green TDD, and a User-Journey +
+E2E-Scenario section on every feature issue. Decisions are captured in this ADR archive.
+
+What is missing is a **machine-readable, uniform front-end to that workflow**:
+
+- Requirements are written in free prose, so two readers (and an AI agent) can interpret the
+  same issue differently. There is no enforced requirement grammar and no stable requirement
+  identifier to trace from spec → code → test.
+- There is no single short file an AI coding agent reads on every invocation; the rules are
+  spread across `CLAUDE.md`, `COLLABORATING.md`, `CODESTYLE.md`, and `CONTRIBUTING.md`.
+- Persona review is valuable but ad-hoc — there is no per-role checklist that gates a spec
+  *before* implementation, so blind spots surface during PR review instead of at spec time.
+- There is no living traceability record and no CI signal that a spec is well-formed.
+
+The project is solo + LLM-driven; spec density and machine-readability are exactly the
+leverage points that make agent output reliable.
+
+## Decision
+
+Adopt Spec-Driven Development, layered **on top of** the existing workflow, not replacing it:
+
+1. **EARS requirements.** Every feature requirement is written in one of the five EARS
+   patterns and carries a per-feature `REQ-NNN` id. (constitution §3; templates/feature-spec.md)
+2. **The spec lives in the Gitea issue body — issue-only, no committed `spec.md`.** A feature's
+   spec (EARS requirements, acceptance criteria, scope) is authored and reviewed in the Gitea
+   issue, the single source of truth (consistent with the established "issue body is the source
+   of truth / don't commit standalone spec files" practice). The only per-feature artifact in
+   git is the RTM row (`REQ-ID → issue # → test`). Durable design decisions still get a
+   `docs/adr/` ADR; an OpenAPI contract or STRIDE threat model is drafted inline in the issue
+   using the `.specify/templates/` as writing aids. `.specify/features/_example/` is a committed
+   template/reference, not a live feature.
+3. **A constitution + AGENTS.md.** `.specify/constitution.md` records the few non-negotiable
+   rules (semantically versioned); `.specify/AGENTS.md` is the short machine-readable file AI
+   agents read every invocation, cross-referencing the constitution rather than duplicating it.
+4. **Persona checklists.** `.specify/personas/*.md` turn the existing rich personas into
+   concise, EARS-aware, pass/fail spec-review checklists that gate a spec before code.
+5. **Living RTM + CI gate.** `.specify/rtm.md` traces every `REQ-NNN` to its issue and test;
+   `.gitea/workflows/sdd-gate.yml` validates any committed OpenAPI contract, lints any committed
+   spec (e.g. the `_example`), reports constitution-change impact, and surfaces RTM drift
+   (non-blocking initially).
+6. **Reuse, don't duplicate.** ADRs stay in `docs/adr/`; persona checklists reference
+   `.claude/personas/`; the Gitea issue templates mirror the feature-spec template.
+
+## Alternatives Considered
+
+| Option | Pros | Cons | Reason rejected |
+|---|---|---|---|
+| Adopt SDD (EARS requirements in the issue + AGENTS.md + constitution), integrated with existing docs | Adds requirement rigor & machine-readability; reuses ADR archive, personas, and the issue-as-spec practice; incremental | Per-feature spec authoring overhead | **Chosen** |
+| No change (keep free-prose issues + persona review) | Zero new process | Ambiguous requirements; no traceability; no single agent-facing file; blind spots found late | Leaves the exact gaps that hurt agent output |
+| Full GitHub Spec Kit | Mature, opinionated tooling | Heavy, opinionated structure that fights the existing Gitea/skill/persona workflow; redundant ADR/persona machinery | Too much to retrofit; conflicts with what already works |
+| BMAD-METHOD | Rich agent-role framework | Large conceptual surface for a solo project; overlaps the existing persona system | Over-engineered for this team size |
+
+## Consequences
+
+- **Cost:** ~30–60 min of spec authoring + structured persona review per feature, before
+  implementation begins.
+- **Gains:** unambiguous, testable requirements; a stable spec→code→test trace; one
+  authoritative agent-facing rules file; review blind spots caught at spec time; better and
+  more consistent AI-agent output (the project's primary delivery mechanism).
+- **Obligations created:**
+  - The constitution is semantically versioned; any change triggers its Sync Impact review.
+  - A new feature follows the workflow in [SPEC_DRIVEN_DEVELOPMENT.md](../../SPEC_DRIVEN_DEVELOPMENT.md).
+  - `rtm.md` is kept in sync as requirements land (CI warns on drift).
+  - The SDD CI jobs start non-blocking and flip to blocking once adoption settles (TODO noted
+    in the workflow).
+- **Non-disruptive:** the existing Gitea-issue, branch/PR, TDD, and persona-review practices
+  are unchanged in spirit — SDD formalises their inputs, it does not replace them.
+
+## References
+
+- [.specify/constitution.md](../../.specify/constitution.md), [.specify/AGENTS.md](../../.specify/AGENTS.md)
+- [SPEC_DRIVEN_DEVELOPMENT.md](../../SPEC_DRIVEN_DEVELOPMENT.md)
+- [COLLABORATING.md](../../COLLABORATING.md), [CONTRIBUTING.md](../../CONTRIBUTING.md)
+- EARS: Mavin et al., "Easy Approach to Requirements Syntax" (2009)
+
+## Revision log
+
+- 2026-06-13 — constitution v1.0.0 ratified with this ADR.

docs/adr/043-derived-person-events.md

@@ -0,0 +1,110 @@
+# ADR-043 — Derived person life-events: on-read assembly strategy
+
+**Status:** Proposed  
+**Date:** 2026-06-13  
+**Issue:** #776 — Timeline: derive person life-events (Geburt/Tod/Heirat)
+
+---
+
+## Context
+
+The Zeitstrahl (family timeline) must surface births, deaths, and marriages alongside
+manually curated `TimelineEvent` rows. This data already exists in the `Person` entity
+(`birthDate`, `deathDate`, `birthDatePrecision`, `deathDatePrecision`) and in
+`PersonRelationship` rows with `relationType = SPOUSE_OF`.
+
+Three architectural decisions needed before implementation could start:
+
+1. **Computation strategy:** should derived events be materialised to the `timeline_events`
+   table, or assembled on every read from the source tables?
+2. **Id format:** how do we give derived events stable, unambiguous ids that cannot collide
+   with real `TimelineEvent` UUIDs and signal read-only semantics to consumers?
+3. **Service contract:** where does the assembly method live, and what is its public API?
+
+---
+
+## Decision 1 — On-read assembly, never persisted
+
+Derived events are computed on every call to `assembleDerivedEvents()` and are never written
+to any table.
+
+**Alternatives rejected:**
+
+| Alternative | Reason rejected |
+|-------------|-----------------|
+| Materialise to `timeline_events` | Requires a synchronisation job or domain-event wiring every time a `Person` or `PersonRelationship` is mutated. Adds complexity, drift risk, and a write path for data that is fundamentally derived. |
+| Separate `derived_events` table | Same sync problem; adds schema migration for data that is a pure projection. |
+| Cache in-process | Adds invalidation complexity for MVP scale (tens to low hundreds of persons). Can be added later if `findAllFamilyMembers()` exceeds ~500 rows. |
+
+**Consequences:**
+- No schema changes. No Flyway migration.
+- The method must be `@Transactional(readOnly = true)` to keep the Hibernate session open
+  across the lazy-association reads that `buildMarriageEvents()` performs via JOIN FETCH.
+- Every caller of `assembleDerivedEvents()` triggers two DB queries: one for family-member
+  persons, one for spouse edges with JOIN FETCH. Acceptable at MVP scale.
+
+---
+
+## Decision 2 — Synthetic prefixed String ids
+
+Derived events receive ids of the form `birth:{personId}`, `death:{personId}`,
+`marriage:{relationshipId}`, where the suffix is the UUID of the source entity.
+
+**Format rules:**
+- `id` field on `TimelineEntryDTO` is typed `String`, NOT `UUID`.
+- `UUID.fromString(derivedEvent.id())` always throws `IllegalArgumentException` — id is
+  structurally non-UUID by construction.
+- The `unique_spouse_pair` DB index (V55) is the authoritative dedup guard for marriages;
+  the in-memory `Set<UUID>` used during assembly is a defensive assertion, not primary
+  enforcement.
+
+**Alternatives rejected:**
+
+| Alternative | Reason rejected |
+|-------------|-----------------|
+| Random UUID for each call | Not stable across calls — consumers (frontend, #5 sort/bucket) could not use ids as stable keys. |
+| UUID typed field with a sentinel namespace (RFC 4122 v5) | Requires hashing; still looks like a UUID and could be confused with real event ids by write endpoints. |
+| Numeric sequence | No natural source sequence; would require a counter, adding state. |
+
+**Consequences:**
+- `TimelineEntryDTO.id` must be `String`. The existing `TimelineEventView.id` is `UUID` and
+  serves a different purpose (CRUD admin view); it is not changed.
+- Any write endpoint that accepts a timeline event id (`PUT`, `DELETE`) must reject ids that
+  do not parse as `UUID` — enforced and tested in issue #5, not here.
+- Ids are deterministic and stable for the lifetime of the source entity, enabling client-side
+  caching and deduplication.
+
+---
+
+## Decision 3 — `assembleDerivedEvents()` as the public cross-issue contract
+
+The assembly method lives on `TimelineService` as a `public` method. Issue #5 (the
+`GET /api/timeline` endpoint) calls it directly on the injected `TimelineService` bean.
+
+**Domain boundary rules enforced by this decision:**
+- `TimelineService` reaches `Person` and `PersonRelationship` data **only through
+  `PersonService.findAllFamilyMembers()` and `RelationshipService.findAllSpouseEdges()`**.
+  It never injects `PersonRepository` or `PersonRelationshipRepository`.
+- The three private builder methods (`buildBirthEvents`, `buildDeathEvents`,
+  `buildMarriageEvents`) are implementation details; only `assembleDerivedEvents()` is public.
+- **Authorization:** `assembleDerivedEvents()` performs no authorization check. The calling
+  endpoint in #5 must enforce `READ_ALL` before invoking this method. Any future caller
+  outside #5 must do the same — this obligation is documented in the Javadoc of the method.
+
+**Alternatives rejected:**
+
+| Alternative | Reason rejected |
+|-------------|-----------------|
+| Separate `DerivedEventService` | Adds a class for a cohesive set of methods that belong to the timeline domain. Timeline owns the DTO shape; splitting it out is premature. |
+| Expose via `PersonService` | Person domain should not know about `TimelineEntryDTO`. Cross-cutting concern belongs in timeline. |
+
+---
+
+## Related decisions
+
+- ADR-039 — Person life-dates stored as `LocalDate` + `DatePrecision` (the source data this
+  issue reads)
+- ADR-040 — Timeline domain data model (establishes the `timeline/` package and
+  `TimelineEvent` entity this issue extends)
+- ADR-036 — Responses as views, never raw entities (why `assembleDerivedEvents()` returns
+  `List<TimelineEntryDTO>`, not raw `Person` or `PersonRelationship` entities)

docs/architecture/c4/l3-backend-timeline.puml

@@ -6,19 +6,28 @@ title Component Diagram: API Backend — Timeline (Zeitstrahl)
 ContainerDb(db, "PostgreSQL", "PostgreSQL 16")
 
 System_Boundary(backend, "API Backend (Spring Boot)") {
-    Component(timelineRepo, "TimelineEventRepository", "Spring Data JPA", "Reads and writes TimelineEvent rows and their persons/documents join tables (timeline_event_persons, timeline_event_documents). Issue #774 ships the repository empty; the per-person filter query lands in #777.")
+    Component(timelineRepo, "TimelineEventRepository", "Spring Data JPA", "Reads and writes TimelineEvent rows and their persons/documents join tables (timeline_event_persons, timeline_event_documents).")
 
-    Component(timelineSvc, "TimelineEventService", "Spring Service (planned, #775)", "Will own curated-event CRUD: assemble TimelineEventView/Summary inside the transaction (lazy ManyToMany + open-in-view=false, per ADR-036/ADR-040), populate createdBy/updatedBy from the session principal, and translate optimistic-lock conflicts to DomainException.conflict.")
+    Component(timelineSvc, "TimelineEventService", "Spring Service", "Owns curated-event CRUD: assembles TimelineEventView inside the transaction (lazy ManyToMany + open-in-view=false, ADR-036/ADR-040), populates createdBy/updatedBy from the session principal, and translates optimistic-lock conflicts to DomainException.conflict. Also exposes assembleDerivedEvents(): computes Geburt/Tod/Heirat TimelineEntryDTOs on read from Person/PersonRelationship data — never persisted (ADR-043).")
-    Component(timelineCtrl, "TimelineEventController", "Spring MVC (planned, #775)", "Will expose /api/timeline reads (READ_ALL) and writes (WRITE_ALL). createdBy/updatedBy are never bound from request bodies (CWE-639).")
+    Component(timelineCtrl, "TimelineEventController", "Spring MVC", "Exposes /api/timeline/events reads (READ_ALL) and writes (WRITE_ALL). createdBy/updatedBy are never bound from request bodies (CWE-639).")
+
+    Component(timelineAssemblySvc, "TimelineService", "Spring Service", "Assembles GET /api/timeline response: merges curated TimelineEvent rows, derived life-events (via TimelineEventService), and archive letters (via DocumentService) into a year-bucketed TimelineDTO. Applies personId, generation, type, fromYear/toYear filters. WITHIN_BAND_ORDER: precision rank desc → date asc → title alpha → id tiebreak.")
+    Component(timelineAssemblyCtrl, "TimelineController", "Spring MVC", "Exposes GET /api/timeline (READ_ALL). Five optional query params: personId, generation (@Min(0)), type (EventType enum), fromYear, toYear. @Validated on class for constraint enforcement.")
 }
 
-System_Ext(documentDomain, "Document domain", "Provides DatePrecision (shared value type) and Document references for linked letters")
+System_Ext(documentDomain, "Document domain", "Provides DatePrecision (shared value type), Document references for linked letters, and getAllForTimeline() bulk fetch")
-System_Ext(personDomain, "Person domain", "Provides Person references for who an event involves")
+System_Ext(personDomain, "Person domain", "Provides Person references (PersonService.findAllFamilyMembers, getPersonsByGeneration, getById) and SPOUSE_OF edges (RelationshipService.findAllSpouseEdges) for derived-event assembly and generation filtering")
 
 Rel(timelineRepo, db, "SQL queries", "JDBC")
-Rel(timelineSvc, timelineRepo, "Reads / writes events (planned)")
+Rel(timelineSvc, timelineRepo, "Reads / writes events")
-Rel(timelineCtrl, timelineSvc, "Delegates to (planned)")
+Rel(timelineCtrl, timelineSvc, "Delegates to")
 Rel(timelineRepo, personDomain, "References persons via join table")
 Rel(timelineRepo, documentDomain, "References documents via join table")
+Rel(timelineSvc, personDomain, "findAllFamilyMembers() + findAllSpouseEdges() for derived-event assembly")
+Rel(timelineAssemblyCtrl, timelineAssemblySvc, "Delegates to")
+Rel(timelineAssemblySvc, timelineRepo, "findAll() for curated events")
+Rel(timelineAssemblySvc, timelineSvc, "assembleDerivedEvents() for derived life-events")
+Rel(timelineAssemblySvc, personDomain, "getPersonsByGeneration(), getById() for generation/personId filters")
+Rel(timelineAssemblySvc, documentDomain, "getAllForTimeline(), getDocumentsBySender(), getDocumentsByReceiver() for letter layer")
 
 @enduml

docs/architecture/c4/l3-frontend-3c-people-stories.puml

@@ -14,6 +14,7 @@ System_Boundary(frontend, "Web Frontend (SvelteKit / SSR)") {
     Component(geschichten, "/geschichten and /geschichten/[id]", "SvelteKit Routes", "Story/Journey list and detail pages. List: GeschichteListRow with REISE badge for JOURNEY type. Detail: dispatches to StoryReader (rich text + persons) or JourneyReader (intro + ordered JourneyItemCard/JourneyInterlude items + empty state) based on GeschichteType. BLOG_WRITE users see edit/delete actions. Loader: GET /api/geschichten, GET /api/geschichten/{id}.")
     Component(geschichtenEdit, "/geschichten/[id]/edit and /geschichten/new", "SvelteKit Routes", "Story editor and creation flow. New: TypeSelector (STORY/JOURNEY radio group with roving tabindex) → StoryCreate (TipTap rich text, person linking, POST /api/geschichten) or JourneyCreate (title + first item). Edit: branches on GeschichteType — STORY opens GeschichteEditor (TipTap body + GeschichteSidebar incl. StoryDocumentPanel: document linking via POST/DELETE /items); JOURNEY opens JourneyEditor (title, intro textarea, ordered JourneyItemRow list with drag-reorder + move-up/down, JourneyAddBar for document/interlude addition, GeschichteSidebar). JourneyEditor mutations: POST/DELETE /items, PUT /items/reorder, PATCH /items/{id}. Requires BLOG_WRITE permission.")
     Component(stammbaum, "/stammbaum", "SvelteKit Route", "Family tree visualisation. Loader: GET /api/network (nodes + edges). Renders interactive family tree from network graph data.")
+    Component(zeitstrahl, "/zeitstrahl", "SvelteKit Route", "Global timeline (Zeitstrahl). SSR loader: GET /api/timeline -> TimelineDTO. Renders lib/timeline/TimelineView (Datum mode): year bands (YearBand) with EventPill / WorldBand / LetterCard, dense-year YearLetterStrip (shared Sparkline + monthHistogram), folded GapSpan for empty-year runs, and an undated bucket. personId prop is the per-person Lebensweg seam (issue #10), undefined here.")
     Component(themen, "/themen", "SvelteKit Route", "Browsable topic index. Shows all root tags as cards with color bars and child rows. ThemenWidget also embedded in the home dashboard (reader + editor sidebar). Loader: GET /api/tags/tree.")
     Component(profilePage, "/profile", "SvelteKit Route", "Current user profile settings. Loader: GET /api/users/me/notification-preferences. Actions: update name/password and notification preferences.")
     Component(userProfile, "/users/[id]", "SvelteKit Route", "Public user profile view. Loader: GET /api/users/{id}.")
@@ -27,6 +28,8 @@ Rel(aktivitaeten, backend, "GET /api/dashboard/activity, GET /api/notifications"
 Rel(geschichten, backend, "GET /api/geschichten, GET /api/geschichten/{id}, DELETE /api/geschichten/{id}", "HTTP / JSON")
 Rel(geschichtenEdit, backend, "GET /api/persons/{id} (pre-populate), POST /api/geschichten, PUT /api/geschichten/{id}, POST/DELETE /api/geschichten/{id}/items, PUT /api/geschichten/{id}/items/reorder, PATCH /api/geschichten/{id}/items/{itemId}", "HTTP / JSON")
 Rel(stammbaum, backend, "GET /api/network", "HTTP / JSON")
+Rel(user, zeitstrahl, "Reads the family timeline", "HTTPS / Browser")
+Rel(zeitstrahl, backend, "GET /api/timeline -> TimelineDTO", "HTTP / JSON")
 Rel(themen, backend, "GET /api/tags/tree", "HTTP / JSON")
 Rel(profilePage, backend, "GET/PUT /api/users/me, notification-preferences", "HTTP / JSON")
 Rel(userProfile, backend, "GET /api/users/{id}", "HTTP / JSON")

frontend/CLAUDE.md

@@ -34,6 +34,7 @@ src/
 │   ├── api/             # Internal API proxies (server-side only)
 │   ├── geschichten/     # Stories (list, [id], [id]/edit, new)
 │   ├── stammbaum/       # Family tree
+│   ├── zeitstrahl/      # Global timeline (Zeitstrahl) — SSR loads /api/timeline, renders lib/timeline
 │   ├── enrich/          # Enrichment workflow ([id], done)
 │   ├── hilfe/transkription/ # Transcription help page
 │   ├── profile/         # User profile settings
@@ -49,6 +50,7 @@ src/
 │   │   ├── relationship/ # Relationship form + chip components
 │   │   └── genealogy/   # Stammbaum (family tree) components
 │   ├── tag/             # Tag domain: TagInput, TagChipList, TagParentPicker
+│   ├── timeline/        # Timeline (Zeitstrahl) domain: TimelineView, YearBand, EventPill, WorldBand, LetterCard, YearLetterStrip, GapSpan; dateLabel + timelineDensity + eventCardConfig (imports $lib/shared only, never document/)
 │   ├── geschichte/      # Geschichte (story) domain: editor + card
 │   ├── notification/    # Notification bell + dropdown + store
 │   ├── activity/        # Activity feed (Chronik) components
@@ -59,8 +61,8 @@ src/
 │   │   ├── hooks/       # Reusable Svelte state hooks (useTypeahead, etc.)
 │   │   ├── server/      # Server-only utilities (locale, session)
 │   │   ├── services/    # Client-side service helpers
-│   │   ├── utils/       # Pure utility functions (date, search, etc.)
+│   │   ├── utils/       # Pure utility functions (date, search, monthBuckets — month-bucket math shared by document chart + timeline strip)
-│   │   ├── primitives/  # Generic UI primitives (BackButton, ProgressRing, etc.)
+│   │   ├── primitives/  # Generic UI primitives (BackButton, ProgressRing, Sparkline, etc.)
 │   │   ├── dashboard/   # Dashboard stat components
 │   │   ├── discussion/  # CommentThread + shared discussion UI
 │   │   ├── help/        # Help/FAQ page components

frontend/e2e/zeitstrahl.spec.ts

@@ -0,0 +1,84 @@
+import { test, expect, type APIRequestContext } from '@playwright/test';
+
+/**
+ * Global /zeitstrahl timeline (#779). Runs against the real stack with the
+ * seeded admin session (auth.setup). Covers the primary journey (nav → page,
+ * timeline inside <main>) and the 320px no-overflow guarantee on a populated
+ * timeline seeded with 25+char correspondent names (REQ-005).
+ */
+
+const stamp = () => new Date().toISOString().replace(/[^0-9]/g, '');
+
+async function createPerson(request: APIRequestContext, firstName: string, lastName: string) {
+	const res = await request.post('/api/persons', {
+		data: { personType: 'PERSON', firstName, lastName }
+	});
+	if (!res.ok()) throw new Error(`create person failed: ${res.status()}`);
+	return (await res.json()).id as string;
+}
+
+/** Seeds one dated letter with long sender/receiver names so it lands on the timeline. */
+async function seedDatedLetter(request: APIRequestContext) {
+	const senderId = await createPerson(
+		request,
+		'Friedrich-Wilhelm',
+		`Maximilian von Habsburg ${stamp()}`
+	);
+	const receiverId = await createPerson(
+		request,
+		'Maria-Magdalena',
+		`Hohenzollern-Sigmaringen ${stamp()}`
+	);
+
+	const createRes = await request.post('/api/documents', {
+		multipart: { title: `E2E Zeitstrahl Brief ${stamp()}` }
+	});
+	if (!createRes.ok()) throw new Error(`create document failed: ${createRes.status()}`);
+	const docId = (await createRes.json()).id as string;
+
+	const put = await request.put(`/api/documents/${docId}`, {
+		multipart: {
+			title: `E2E Zeitstrahl Brief ${stamp()}`,
+			documentDate: '1915-06-15',
+			metaDatePrecision: 'DAY',
+			senderId,
+			receiverIds: receiverId
+		}
+	});
+	if (!put.ok()) throw new Error(`update document failed: ${put.status()}`);
+}
+
+test.describe('Zeitstrahl — global timeline (#779)', () => {
+	test('nav link opens /zeitstrahl and the timeline lives in <main>', async ({ page }) => {
+		await page.goto('/');
+		await page.getByRole('navigation').getByRole('link', { name: 'Zeitstrahl' }).first().click();
+		await expect(page).toHaveURL(/\/zeitstrahl$/);
+		await expect(page.getByRole('heading', { level: 1, name: 'Zeitstrahl' })).toBeVisible();
+
+		// The main landmark contains either the populated <ol> or the empty state.
+		const main = page.getByRole('main');
+		const ol = main.locator('ol');
+		const empty = main.getByText('Noch keine Ereignisse.');
+		await expect(async () => {
+			const populated = (await ol.count()) > 0;
+			const isEmpty = await empty.isVisible().catch(() => false);
+			expect(populated || isEmpty).toBe(true);
+		}).toPass();
+	});
+
+	test('no horizontal overflow at 320px with long correspondent names (REQ-005)', async ({
+		page,
+		request
+	}) => {
+		await seedDatedLetter(request);
+
+		await page.setViewportSize({ width: 320, height: 900 });
+		await page.goto('/zeitstrahl');
+
+		// Populated: the seeded letter puts the timeline <ol> in the DOM.
+		await expect(page.getByRole('main').locator('ol')).toHaveCount(1);
+
+		const scrollWidth = await page.evaluate(() => document.body.scrollWidth);
+		expect(scrollWidth).toBe(320);
+	});
+});

frontend/eslint.config.js

@@ -158,6 +158,7 @@ export default defineConfig(
 				{ type: 'ocr', pattern: 'src/lib/ocr/**' },
 				{ type: 'activity', pattern: 'src/lib/activity/**' },
 				{ type: 'conversation', pattern: 'src/lib/conversation/**' },
+				{ type: 'timeline', pattern: 'src/lib/timeline/**' },
 				{ type: 'shared', pattern: 'src/lib/shared/**' },
 				{ type: 'routes', pattern: 'src/routes/**' }
 			]
@@ -198,6 +199,7 @@ export default defineConfig(
 						{ from: { type: 'user' }, allow: { to: { type: ['shared'] } } },
 						{ from: { type: 'notification' }, allow: { to: { type: ['shared'] } } },
 						{ from: { type: 'conversation' }, allow: { to: { type: ['shared'] } } },
+						{ from: { type: 'timeline' }, allow: { to: { type: ['shared'] } } },
 						{ from: { type: 'shared' }, allow: { to: { type: ['shared'] } } },
 						{
 							from: { type: 'routes' },
@@ -213,6 +215,7 @@ export default defineConfig(
 										'ocr',
 										'activity',
 										'conversation',
+										'timeline',
 										'shared'
 									]
 								}

frontend/messages/de.json

@@ -1032,6 +1032,20 @@
 	"bulk_edit_count_pill": "{count} werden bearbeitet",
 	"nav_stammbaum": "Stammbaum",
 	"nav_geschichten": "Geschichten",
+	"nav_zeitstrahl": "Zeitstrahl",
+	"timeline_heading": "Zeitstrahl",
+	"timeline_empty_state": "Noch keine Ereignisse.",
+	"timeline_undated_section": "Ohne Datum",
+	"timeline_unknown_person": "Unbekannt",
+	"timeline_gap_empty": "keine Einträge",
+	"timeline_letters_count": "{count} Briefe",
+	"timeline_strip_expand": "Briefe anzeigen",
+	"timeline_range_aria": "Zeitraum: {from} bis {to}",
+	"timeline_layer_world": "Weltgeschehen",
+	"timeline_layer_family": "Familie",
+	"timeline_derived_birth": "Geburt",
+	"timeline_derived_death": "Tod",
+	"timeline_derived_marriage": "Heirat",
 	"error_geschichte_not_found": "Die Geschichte wurde nicht gefunden.",
 	"error_journey_item_not_found": "Der Reise-Eintrag wurde nicht gefunden.",
 	"error_journey_item_position_conflict": "Die Reihenfolge wurde gerade von jemand anderem geändert – bitte laden Sie die Seite neu.",
@@ -1237,6 +1251,10 @@
 	"error_journey_note_too_long": "Die Notiz ist zu lang (maximal 2000 Zeichen).",
 	"error_geschichte_title_too_long": "Der Titel ist zu lang (maximal 255 Zeichen).",
 	"error_geschichte_intro_too_long": "Die Einleitung ist zu lang (maximal 4000 Zeichen).",
+	"error_timeline_event_not_found": "Zeitleistenereignis nicht gefunden.",
+	"error_timeline_event_conflict": "Dieses Ereignis wurde zwischenzeitlich geändert. Bitte neu laden.",
+	"error_timeline_title_too_long": "Der Titel ist zu lang (maximal 255 Zeichen).",
+	"error_conflict": "Der Datensatz wurde zwischenzeitlich geändert. Bitte neu laden.",
 	"person_unknown": "[Unbekannt]",
 	"error_journey_document_already_added": "Dieser Brief ist bereits in der Lesereise enthalten.",
 	"error_geschichte_type_immutable": "Der Typ einer Geschichte kann nach der Erstellung nicht mehr geändert werden."

frontend/messages/en.json

@@ -1032,6 +1032,20 @@
 	"bulk_edit_count_pill": "{count} will be edited",
 	"nav_stammbaum": "Family tree",
 	"nav_geschichten": "Stories",
+	"nav_zeitstrahl": "Timeline",
+	"timeline_heading": "Timeline",
+	"timeline_empty_state": "No events yet.",
+	"timeline_undated_section": "Without Date",
+	"timeline_unknown_person": "Unknown",
+	"timeline_gap_empty": "no entries",
+	"timeline_letters_count": "{count} letters",
+	"timeline_strip_expand": "Show letters",
+	"timeline_range_aria": "Period: {from} to {to}",
+	"timeline_layer_world": "World events",
+	"timeline_layer_family": "Family",
+	"timeline_derived_birth": "Birth",
+	"timeline_derived_death": "Death",
+	"timeline_derived_marriage": "Marriage",
 	"error_geschichte_not_found": "The story was not found.",
 	"error_journey_item_not_found": "The journey item was not found.",
 	"error_journey_item_position_conflict": "The order was just changed by someone else — please reload the page.",
@@ -1237,6 +1251,10 @@
 	"error_journey_note_too_long": "The note is too long (maximum 2000 characters).",
 	"error_geschichte_title_too_long": "The title is too long (maximum 255 characters).",
 	"error_geschichte_intro_too_long": "The introduction is too long (maximum 4000 characters).",
+	"error_timeline_event_not_found": "Timeline event not found.",
+	"error_timeline_event_conflict": "This event was changed in the meantime. Please reload.",
+	"error_timeline_title_too_long": "The title is too long (maximum 255 characters).",
+	"error_conflict": "The record was changed in the meantime. Please reload.",
 	"person_unknown": "[Unknown]",
 	"error_journey_document_already_added": "This letter is already included in the reading journey.",
 	"error_geschichte_type_immutable": "The type of a story cannot be changed after creation."

frontend/messages/es.json

@@ -1032,6 +1032,20 @@
 	"bulk_edit_count_pill": "Se editarán {count}",
 	"nav_stammbaum": "Árbol genealógico",
 	"nav_geschichten": "Historias",
+	"nav_zeitstrahl": "Línea de tiempo",
+	"timeline_heading": "Línea de tiempo",
+	"timeline_empty_state": "Aún no hay eventos.",
+	"timeline_undated_section": "Sin Fecha",
+	"timeline_unknown_person": "Desconocido",
+	"timeline_gap_empty": "sin entradas",
+	"timeline_letters_count": "{count} cartas",
+	"timeline_strip_expand": "Mostrar cartas",
+	"timeline_range_aria": "Período: {from} a {to}",
+	"timeline_layer_world": "Acontecimientos mundiales",
+	"timeline_layer_family": "Familia",
+	"timeline_derived_birth": "Nacimiento",
+	"timeline_derived_death": "Fallecimiento",
+	"timeline_derived_marriage": "Matrimonio",
 	"error_geschichte_not_found": "No se encontró la historia.",
 	"error_journey_item_not_found": "No se encontró el elemento del viaje.",
 	"error_journey_item_position_conflict": "El orden fue cambiado por otra persona — por favor recargue la página.",
@@ -1237,6 +1251,10 @@
 	"error_journey_note_too_long": "La nota es demasiado larga (máximo 2000 caracteres).",
 	"error_geschichte_title_too_long": "El título es demasiado largo (máximo 255 caracteres).",
 	"error_geschichte_intro_too_long": "La introducción es demasiado larga (máximo 4000 caracteres).",
+	"error_timeline_event_not_found": "Evento de la línea de tiempo no encontrado.",
+	"error_timeline_event_conflict": "Este evento se modificó mientras tanto. Vuelve a cargar.",
+	"error_timeline_title_too_long": "El título es demasiado largo (máximo 255 caracteres).",
+	"error_conflict": "El registro se modificó mientras tanto. Vuelve a cargar.",
 	"person_unknown": "[Desconocido]",
 	"error_journey_document_already_added": "Esta carta ya está incluida en el viaje de lectura.",
 	"error_geschichte_type_immutable": "El tipo de una historia no se puede cambiar después de su creación."

frontend/src/lib/document/README.md

@@ -30,6 +30,7 @@ Sub-folders: `annotation/`, `transcription/`, `viewer/`.
 - `tag/TagInput.svelte` — tag chip input
 - `ocr/OcrProgress.svelte` — job status indicator in the document header
 - `shared/primitives/BackButton.svelte`, `shared/discussion/` — shared UI
+- `shared/utils/monthBuckets.ts` — the density chart's pure month-bucket math (boundaries, gap-fill, year aggregation, axis ticks) now lives in `shared/` so the `timeline/` domain can reuse it; `document/timeline.ts` keeps only the `/api/documents/density` glue (`fetchDensity`, `buildDensityUrl`)
 
 ## Backend counterpart
 

frontend/src/lib/document/TimelineBars.svelte

@@ -1,6 +1,6 @@
 <script lang="ts">
 import * as m from '$lib/paraglide/messages.js';
-import { formatTickLabel } from '$lib/document/timeline';
+import { formatTickLabel } from '$lib/shared/utils/monthBuckets';
 import { getLocale } from '$lib/paraglide/runtime';
 import type { components } from '$lib/generated/api';
 

frontend/src/lib/document/TimelineDensityFilter.svelte

@@ -7,7 +7,7 @@ import {
 	selectionBoundaryFrom,
 	selectionBoundaryTo,
 	formatTickLabel
-} from '$lib/document/timeline';
+} from '$lib/shared/utils/monthBuckets';
 import { createTimelineDrag } from '$lib/document/useTimelineDrag.svelte';
 import { getLocale } from '$lib/paraglide/runtime';
 import TimelineBars from '$lib/document/TimelineBars.svelte';

frontend/src/lib/document/TimelineDensityFilter.svelte.spec.ts

@@ -3,7 +3,7 @@ import { cleanup, render } from 'vitest-browser-svelte';
 import { page } from 'vitest/browser';
 import { tick } from 'svelte';
 import TimelineDensityFilter from './TimelineDensityFilter.svelte';
-import { formatTickLabel } from './timeline';
+import { formatTickLabel } from '$lib/shared/utils/monthBuckets';
 import { getLocale } from '$lib/paraglide/runtime';
 import type { components } from '$lib/generated/api';
 

frontend/src/lib/document/TimelineXAxis.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-import { formatTickLabel, tickIndicesFor } from '$lib/document/timeline';
+import { formatTickLabel, tickIndicesFor } from '$lib/shared/utils/monthBuckets';
 import { getLocale } from '$lib/paraglide/runtime';
 import type { components } from '$lib/generated/api';
 

frontend/src/lib/document/timeline.spec.ts

@@ -1,191 +1,5 @@
 import { describe, it, expect, vi } from 'vitest';
-import {
+import { fetchDensity, buildDensityUrl } from './timeline';
-	monthBoundaryFrom,
-	monthBoundaryTo,
-	buildMonthSequence,
-	fillDensityGaps,
-	fetchDensity,
-	buildDensityUrl,
-	aggregateToYears,
-	selectionBoundaryFrom,
-	selectionBoundaryTo,
-	clipBucketsToRange,
-	tickIndicesFor,
-	formatTickLabel
-} from './timeline';
-
-describe('monthBoundaryFrom', () => {
-	it('returns the first day of the given month', () => {
-		expect(monthBoundaryFrom('1915-08')).toBe('1915-08-01');
-	});
-
-	it('handles January', () => {
-		expect(monthBoundaryFrom('1920-01')).toBe('1920-01-01');
-	});
-});
-
-describe('monthBoundaryTo', () => {
-	it('returns the last day of a 31-day month', () => {
-		expect(monthBoundaryTo('1915-08')).toBe('1915-08-31');
-	});
-
-	it('returns the last day of a 30-day month', () => {
-		expect(monthBoundaryTo('1915-04')).toBe('1915-04-30');
-	});
-
-	it('returns 28 for February in a non-leap year', () => {
-		expect(monthBoundaryTo('1915-02')).toBe('1915-02-28');
-	});
-
-	it('returns 29 for February in a leap year', () => {
-		expect(monthBoundaryTo('1916-02')).toBe('1916-02-29');
-	});
-});
-
-describe('buildMonthSequence', () => {
-	it('returns a single month when min and max are in the same month', () => {
-		expect(buildMonthSequence('1915-08-03', '1915-08-22')).toEqual(['1915-08']);
-	});
-
-	it('returns months from minDate through maxDate inclusive', () => {
-		expect(buildMonthSequence('1915-08-03', '1915-11-15')).toEqual([
-			'1915-08',
-			'1915-09',
-			'1915-10',
-			'1915-11'
-		]);
-	});
-
-	it('crosses year boundaries correctly', () => {
-		expect(buildMonthSequence('1915-11-30', '1916-02-01')).toEqual([
-			'1915-11',
-			'1915-12',
-			'1916-01',
-			'1916-02'
-		]);
-	});
-
-	it('returns empty array when minDate or maxDate is null', () => {
-		expect(buildMonthSequence(null, '1915-08-01')).toEqual([]);
-		expect(buildMonthSequence('1915-08-01', null)).toEqual([]);
-		expect(buildMonthSequence(null, null)).toEqual([]);
-	});
-});
-
-describe('fillDensityGaps', () => {
-	it('returns empty array when minDate or maxDate is null', () => {
-		expect(fillDensityGaps([], null, null)).toEqual([]);
-	});
-
-	it('preserves existing buckets and adds zero-count buckets for missing months', () => {
-		const buckets = [
-			{ month: '1915-08', count: 5 },
-			{ month: '1915-11', count: 2 }
-		];
-
-		const result = fillDensityGaps(buckets, '1915-08-03', '1915-11-30');
-
-		expect(result).toEqual([
-			{ month: '1915-08', count: 5 },
-			{ month: '1915-09', count: 0 },
-			{ month: '1915-10', count: 0 },
-			{ month: '1915-11', count: 2 }
-		]);
-	});
-
-	it('returns all-zero sequence when buckets array is empty', () => {
-		const result = fillDensityGaps([], '1915-08-03', '1915-10-15');
-
-		expect(result).toEqual([
-			{ month: '1915-08', count: 0 },
-			{ month: '1915-09', count: 0 },
-			{ month: '1915-10', count: 0 }
-		]);
-	});
-
-	it('keeps results sorted chronologically even when buckets arrive out of order', () => {
-		const buckets = [
-			{ month: '1915-10', count: 3 },
-			{ month: '1915-08', count: 1 }
-		];
-
-		const result = fillDensityGaps(buckets, '1915-08-01', '1915-10-31');
-
-		expect(result.map((b) => b.month)).toEqual(['1915-08', '1915-09', '1915-10']);
-	});
-});
-
-describe('aggregateToYears', () => {
-	it('returns empty array for empty input', () => {
-		expect(aggregateToYears([])).toEqual([]);
-	});
-
-	it('sums counts within the same year', () => {
-		const result = aggregateToYears([
-			{ month: '1915-08', count: 5 },
-			{ month: '1915-09', count: 2 },
-			{ month: '1915-10', count: 8 }
-		]);
-		expect(result).toEqual([{ month: '1915', count: 15 }]);
-	});
-
-	it('produces one bucket per distinct year, sorted chronologically', () => {
-		const result = aggregateToYears([
-			{ month: '1916-01', count: 3 },
-			{ month: '1915-08', count: 5 },
-			{ month: '1916-04', count: 7 },
-			{ month: '1914-12', count: 1 }
-		]);
-		expect(result).toEqual([
-			{ month: '1914', count: 1 },
-			{ month: '1915', count: 5 },
-			{ month: '1916', count: 10 }
-		]);
-	});
-});
-
-describe('clipBucketsToRange', () => {
-	const buckets = [
-		{ month: '1915-08', count: 5 },
-		{ month: '1915-09', count: 2 },
-		{ month: '1915-10', count: 8 },
-		{ month: '1915-11', count: 3 }
-	];
-
-	it('returns the original buckets when range bounds are null', () => {
-		expect(clipBucketsToRange(buckets, null, null)).toBe(buckets);
-	});
-
-	it('keeps only buckets whose month falls within the range', () => {
-		expect(clipBucketsToRange(buckets, '1915-09-01', '1915-10-31')).toEqual([
-			{ month: '1915-09', count: 2 },
-			{ month: '1915-10', count: 8 }
-		]);
-	});
-
-	it('returns an empty array when the range excludes everything', () => {
-		expect(clipBucketsToRange(buckets, '1916-01-01', '1916-12-31')).toEqual([]);
-	});
-
-	it('treats partial dates correctly when bounds cross month boundaries', () => {
-		expect(clipBucketsToRange(buckets, '1915-09-15', '1915-10-15')).toEqual([
-			{ month: '1915-09', count: 2 },
-			{ month: '1915-10', count: 8 }
-		]);
-	});
-});
-
-describe('selectionBoundaryFrom / To', () => {
-	it('handles month labels (YYYY-MM)', () => {
-		expect(selectionBoundaryFrom('1915-08')).toBe('1915-08-01');
-		expect(selectionBoundaryTo('1915-08')).toBe('1915-08-31');
-	});
-
-	it('handles year labels (YYYY)', () => {
-		expect(selectionBoundaryFrom('1915')).toBe('1915-01-01');
-		expect(selectionBoundaryTo('1915')).toBe('1915-12-31');
-	});
-});
 
 describe('buildDensityUrl', () => {
 	it('returns the bare endpoint when no filters provided', () => {
@@ -309,84 +123,3 @@ describe('fetchDensity', () => {
 		warn.mockRestore();
 	});
 });
-
-describe('tickIndicesFor', () => {
-	it('returns no indices for an empty bucket list', () => {
-		expect(tickIndicesFor([])).toEqual([]);
-	});
-
-	it('picks years divisible by 25 when the year span exceeds 120', () => {
-		const buckets = Array.from({ length: 150 }, (_, i) => ({
-			month: String(1875 + i),
-			count: 1
-		}));
-		const ticks = tickIndicesFor(buckets);
-		const labels = ticks.map((i) => buckets[i].month);
-		expect(labels).toEqual(['1875', '1900', '1925', '1950', '1975', '2000']);
-	});
-
-	it('picks years divisible by 10 for medium ranges (~50 years)', () => {
-		const buckets = Array.from({ length: 50 }, (_, i) => ({
-			month: String(1900 + i),
-			count: 1
-		}));
-		const ticks = tickIndicesFor(buckets);
-		const labels = ticks.map((i) => buckets[i].month);
-		expect(labels).toEqual(['1900', '1910', '1920', '1930', '1940']);
-	});
-
-	it('picks January boundaries for long month ranges', () => {
-		const buckets = [
-			{ month: '1914-08', count: 1 },
-			{ month: '1914-09', count: 1 },
-			{ month: '1914-10', count: 1 },
-			{ month: '1914-11', count: 1 },
-			{ month: '1914-12', count: 1 },
-			{ month: '1915-01', count: 1 },
-			{ month: '1915-02', count: 1 },
-			{ month: '1915-03', count: 1 },
-			{ month: '1915-04', count: 1 },
-			{ month: '1915-05', count: 1 },
-			{ month: '1915-06', count: 1 },
-			{ month: '1915-07', count: 1 },
-			{ month: '1915-08', count: 1 },
-			{ month: '1915-09', count: 1 },
-			{ month: '1915-10', count: 1 },
-			{ month: '1915-11', count: 1 },
-			{ month: '1915-12', count: 1 },
-			{ month: '1916-01', count: 1 },
-			{ month: '1916-02', count: 1 }
-		];
-		const ticks = tickIndicesFor(buckets);
-		expect(ticks.map((i) => buckets[i].month)).toEqual(['1915-01', '1916-01']);
-	});
-
-	it('falls back to evenly spaced ticks for short month ranges (12 months)', () => {
-		const buckets = Array.from({ length: 12 }, (_, i) => ({
-			month: `1905-${String(i + 1).padStart(2, '0')}`,
-			count: 1
-		}));
-		const ticks = tickIndicesFor(buckets);
-		expect(ticks.length).toBeGreaterThanOrEqual(5);
-		expect(ticks.length).toBeLessThanOrEqual(7);
-		expect(ticks[0]).toBe(0);
-	});
-});
-
-describe('formatTickLabel', () => {
-	it('returns the year string unchanged for year labels', () => {
-		expect(formatTickLabel('1905', 'en-US')).toBe('1905');
-	});
-
-	it('formats month labels with the year by default', () => {
-		const result = formatTickLabel('1905-06', 'en-US');
-		expect(result).toMatch(/Jun/);
-		expect(result).toMatch(/1905/);
-	});
-
-	it('omits the year when omitYear is true', () => {
-		const result = formatTickLabel('1905-06', 'en-US', true);
-		expect(result).toMatch(/Jun/);
-		expect(result).not.toMatch(/1905/);
-	});
-});

frontend/src/lib/document/timeline.ts

@@ -12,160 +12,6 @@ export type DensityState = {
 const SKIP: DensityState = { density: null, minDate: null, maxDate: null };
 const EMPTY: DensityState = { density: [], minDate: null, maxDate: null };
 
-export function monthBoundaryFrom(yearMonth: string): string {
-	return `${yearMonth}-01`;
-}
-
-export function monthBoundaryTo(yearMonth: string): string {
-	const [year, month] = yearMonth.split('-').map(Number);
-	// Day 0 of `month + 1` rolls back to the last day of `month` — so passing
-	// `month` (1-indexed) into `Date.UTC(year, month, 0)` lands on the last day
-	// of that month. Handles 28/29/30/31 and leap years without a lookup table.
-	const lastDay = new Date(Date.UTC(year, month, 0)).getUTCDate();
-	return `${yearMonth}-${String(lastDay).padStart(2, '0')}`;
-}
-
-export function buildMonthSequence(minDate: string | null, maxDate: string | null): string[] {
-	if (!minDate || !maxDate) return [];
-
-	const [minY, minM] = minDate.split('-').map(Number);
-	const [maxY, maxM] = maxDate.split('-').map(Number);
-
-	const sequence: string[] = [];
-	let year = minY;
-	let month = minM;
-
-	while (year < maxY || (year === maxY && month <= maxM)) {
-		sequence.push(`${year}-${String(month).padStart(2, '0')}`);
-		month += 1;
-		if (month > 12) {
-			month = 1;
-			year += 1;
-		}
-	}
-
-	return sequence;
-}
-
-export function fillDensityGaps(
-	buckets: MonthBucket[],
-	minDate: string | null,
-	maxDate: string | null
-): MonthBucket[] {
-	const sequence = buildMonthSequence(minDate, maxDate);
-	if (sequence.length === 0) return [];
-
-	const counts = new Map(buckets.map((b) => [b.month, b.count]));
-	return sequence.map((month) => ({ month, count: counts.get(month) ?? 0 }));
-}
-
-/**
- * Returns only the month buckets whose YYYY-MM falls inside the provided
- * `[fromInclusive, toInclusive]` ISO date range. When either bound is null the
- * input array is returned unchanged. Used by the timeline's zoom-in tool to
- * narrow the visible bars without refetching data.
- *
- * @internal Sole call site is `TimelineDensityFilter.svelte`. Exported so the
- * unit suite (`timeline.spec.ts`) can pin the boundary semantics directly.
- */
-export function clipBucketsToRange(
-	buckets: MonthBucket[],
-	fromInclusive: string | null,
-	toInclusive: string | null
-): MonthBucket[] {
-	if (!fromInclusive || !toInclusive) return buckets;
-	const fromMonth = fromInclusive.slice(0, 7);
-	const toMonth = toInclusive.slice(0, 7);
-	return buckets.filter((b) => b.month >= fromMonth && b.month <= toMonth);
-}
-
-/**
- * Aggregates month-granular buckets into one entry per year. Month strings are
- * truncated to "YYYY" and counts are summed. Used when the date span is too
- * long for month-granular bars to render at a clickable size.
- */
-export function aggregateToYears(buckets: MonthBucket[]): MonthBucket[] {
-	const totals = new Map<string, number>();
-	for (const b of buckets) {
-		const year = b.month.slice(0, 4);
-		totals.set(year, (totals.get(year) ?? 0) + b.count);
-	}
-	return Array.from(totals.entries())
-		.map(([year, count]) => ({ month: year, count }))
-		.sort((a, b) => a.month.localeCompare(b.month));
-}
-
-/**
- * Boundary helpers for selection. Accept either "YYYY-MM" (month) or "YYYY"
- * (year) and return the matching LocalDate string.
- */
-export function selectionBoundaryFrom(label: string): string {
-	return label.length === 4 ? `${label}-01-01` : `${label}-01`;
-}
-
-export function selectionBoundaryTo(label: string): string {
-	if (label.length === 4) return `${label}-12-31`;
-	return monthBoundaryTo(label);
-}
-
-/**
- * Picks bucket indices that should get an X-axis tick label. The strategy adapts
- * to whether bars are years or months and how many are visible:
- *  - Year bars: pick years divisible by a step that scales with range length
- *    (every 25 yrs for >120 bars, every 20 / 10 / 5 / 1 below).
- *  - Month bars: prefer January boundaries (year breaks). For ≤18 bars (e.g.
- *    one year zoomed in to months), fall back to evenly spaced ticks so we
- *    show ~6 labels even when no January boundary exists.
- */
-export function tickIndicesFor(filled: MonthBucket[]): number[] {
-	if (filled.length === 0) return [];
-	const isYearMode = filled[0].month.length === 4;
-	const indices: number[] = [];
-
-	if (isYearMode) {
-		const years = filled.length;
-		const step =
-			years > 120 ? 25 : years > 60 ? 20 : years > 30 ? 10 : years > 12 ? 5 : years > 6 ? 2 : 1;
-		for (let i = 0; i < filled.length; i++) {
-			const year = parseInt(filled[i].month, 10);
-			if (year % step === 0) indices.push(i);
-		}
-		return indices;
-	}
-
-	if (filled.length <= 18) {
-		const step = Math.max(1, Math.round(filled.length / 6));
-		for (let i = 0; i < filled.length; i += step) indices.push(i);
-		return indices;
-	}
-
-	// Long month range — pick January boundaries (year breaks).
-	for (let i = 0; i < filled.length; i++) {
-		if (filled[i].month.endsWith('-01')) indices.push(i);
-	}
-	// Fallback if there's no January in the visible range (rare): even spacing.
-	if (indices.length === 0) {
-		const step = Math.max(1, Math.round(filled.length / 6));
-		for (let i = 0; i < filled.length; i += step) indices.push(i);
-	}
-	return indices;
-}
-
-/**
- * Formats a bucket month label ("YYYY" or "YYYY-MM") for the X-axis. When
- * `omitYear` is true the year is dropped so a 12-month zoomed view reads as
- * "Jan", "Feb", … without repetition.
- */
-export function formatTickLabel(label: string, locale?: string, omitYear = false): string {
-	if (label.length === 4) return label;
-	const [yearStr, monthStr] = label.split('-');
-	const date = new Date(parseInt(yearStr, 10), parseInt(monthStr, 10) - 1, 1);
-	const opts: Intl.DateTimeFormatOptions = omitYear
-		? { month: 'short' }
-		: { month: 'short', year: 'numeric' };
-	return new Intl.DateTimeFormat(locale, opts).format(date);
-}
-
 /**
  * The subset of /documents URL params that should narrow the density chart.
  * Date bounds (`from`/`to`) are intentionally excluded — see

frontend/src/lib/generated/api.ts

@@ -52,6 +52,22 @@ export interface paths {
         patch?: never;
         trace?: never;
     };
+    "/api/timeline/events/{id}": {
+        parameters: {
+            query?: never;
+            header?: never;
+            path?: never;
+            cookie?: never;
+        };
+        get: operations["getEvent"];
+        put: operations["update"];
+        post?: never;
+        delete: operations["delete"];
+        options?: never;
+        head?: never;
+        patch?: never;
+        trace?: never;
+    };
     "/api/tags/{id}": {
         parameters: {
             query?: never;
@@ -232,6 +248,22 @@ export interface paths {
         patch?: never;
         trace?: never;
     };
+    "/api/timeline/events": {
+        parameters: {
+            query?: never;
+            header?: never;
+            path?: never;
+            cookie?: never;
+        };
+        get?: never;
+        put?: never;
+        post: operations["create"];
+        delete?: never;
+        options?: never;
+        head?: never;
+        patch?: never;
+        trace?: never;
+    };
     "/api/tags/{id}/merge": {
         parameters: {
             query?: never;
@@ -433,7 +465,7 @@ export interface paths {
         };
         get: operations["list"];
         put?: never;
-        post: operations["create"];
+        post: operations["create_1"];
         delete?: never;
         options?: never;
         head?: never;
@@ -834,10 +866,10 @@ export interface paths {
         get: operations["getById"];
         put?: never;
         post?: never;
-        delete: operations["delete"];
+        delete: operations["delete_1"];
         options?: never;
         head?: never;
-        patch: operations["update"];
+        patch: operations["update_1"];
         trace?: never;
     };
     "/api/geschichten/{id}/items/{itemId}": {
@@ -1000,6 +1032,22 @@ export interface paths {
         patch?: never;
         trace?: never;
     };
+    "/api/timeline": {
+        parameters: {
+            query?: never;
+            header?: never;
+            path?: never;
+            cookie?: never;
+        };
+        get: operations["getTimeline"];
+        put?: never;
+        post?: never;
+        delete?: never;
+        options?: never;
+        head?: never;
+        patch?: never;
+        trace?: never;
+    };
     "/api/tags": {
         parameters: {
             query?: never;
@@ -1691,6 +1739,61 @@ export interface components {
             notifyOnReply?: boolean;
             notifyOnMention?: boolean;
         };
+        TimelineEventRequest: {
+            title: string;
+            /** @enum {string} */
+            type: "PERSONAL" | "HISTORICAL";
+            /** Format: date */
+            eventDate: string;
+            /** @enum {string} */
+            precision?: "DAY" | "MONTH" | "SEASON" | "YEAR" | "RANGE" | "APPROX" | "UNKNOWN";
+            /** Format: date */
+            eventDateEnd?: string;
+            description?: string;
+            /** Format: int64 */
+            version?: number;
+            personIds?: string[];
+            documentIds?: string[];
+        };
+        DocumentRef: {
+            /** Format: uuid */
+            id: string;
+            title: string;
+            /** Format: date */
+            documentDate?: string;
+        };
+        PersonView: {
+            /** Format: uuid */
+            id: string;
+            firstName?: string;
+            lastName?: string;
+        };
+        TimelineEventView: {
+            /** Format: uuid */
+            id: string;
+            title: string;
+            /** @enum {string} */
+            type: "PERSONAL" | "HISTORICAL";
+            /** Format: date */
+            eventDate: string;
+            /** @enum {string} */
+            precision: "DAY" | "MONTH" | "SEASON" | "YEAR" | "RANGE" | "APPROX" | "UNKNOWN";
+            /** Format: date */
+            eventDateEnd?: string;
+            description?: string;
+            /** Format: int64 */
+            version: number;
+            /** Format: uuid */
+            createdBy: string;
+            /** Format: date-time */
+            createdAt: string;
+            /** Format: uuid */
+            updatedBy: string;
+            /** Format: date-time */
+            updatedAt: string;
+            persons: components["schemas"]["PersonView"][];
+            documents: components["schemas"]["DocumentRef"][];
+        };
         TagUpdateDTO: {
             name?: string;
             /** Format: uuid */
@@ -2060,12 +2163,6 @@ export interface components {
             /** Format: date-time */
             updatedAt: string;
         };
-        PersonView: {
-            /** Format: uuid */
-            id: string;
-            firstName?: string;
-            lastName?: string;
-        };
         JourneyItemCreateDTO: {
             /** Format: uuid */
             documentId?: string;
@@ -2332,6 +2429,38 @@ export interface components {
             contributors: components["schemas"]["ActivityActorDTO"][];
             hasMoreContributors: boolean;
         };
+        TimelineDTO: {
+            years: components["schemas"]["TimelineYearDTO"][];
+            undated: components["schemas"]["TimelineEntryDTO"][];
+        };
+        TimelineEntryDTO: {
+            /** @enum {string} */
+            kind: "EVENT" | "LETTER";
+            /** @enum {string} */
+            precision: "DAY" | "MONTH" | "SEASON" | "YEAR" | "RANGE" | "APPROX" | "UNKNOWN";
+            derived: boolean;
+            senderName: string;
+            receiverName: string;
+            /** Format: date */
+            eventDate?: string;
+            /** Format: date */
+            eventDateEnd?: string;
+            title?: string;
+            /** @enum {string} */
+            type?: "PERSONAL" | "HISTORICAL";
+            /** Format: uuid */
+            eventId?: string;
+            /** Format: uuid */
+            documentId?: string;
+            linkedPersonIds?: string[];
+            /** @enum {string} */
+            derivedType?: "BIRTH" | "DEATH" | "MARRIAGE";
+        };
+        TimelineYearDTO: {
+            /** Format: int32 */
+            year: number;
+            entries: components["schemas"]["TimelineEntryDTO"][];
+        };
         TagTreeNodeDTO: {
             /** Format: uuid */
             id: string;
@@ -2387,10 +2516,10 @@ export interface components {
             birthDatePrecision?: "DAY" | "MONTH" | "SEASON" | "YEAR" | "RANGE" | "APPROX" | "UNKNOWN";
             /** Format: date */
             deathDate?: string;
-            /** @enum {string} */
-            deathDatePrecision?: "DAY" | "MONTH" | "SEASON" | "YEAR" | "RANGE" | "APPROX" | "UNKNOWN";
             personType?: string;
             familyMember?: boolean;
+            /** @enum {string} */
+            deathDatePrecision?: "DAY" | "MONTH" | "SEASON" | "YEAR" | "RANGE" | "APPROX" | "UNKNOWN";
             provisional?: boolean;
             /** Format: int32 */
             birthYear?: number;
@@ -2498,10 +2627,10 @@ export interface components {
             /** Format: int32 */
             number?: number;
             sort?: components["schemas"]["SortObject"];
-            /** Format: int32 */
-            numberOfElements?: number;
             first?: boolean;
             last?: boolean;
+            /** Format: int32 */
+            numberOfElements?: number;
             empty?: boolean;
         };
         PageableObject: {
@@ -2885,6 +3014,74 @@ export interface operations {
             };
         };
     };
+    getEvent: {
+        parameters: {
+            query?: never;
+            header?: never;
+            path: {
+                id: string;
+            };
+            cookie?: never;
+        };
+        requestBody?: never;
+        responses: {
+            /** @description OK */
+            200: {
+                headers: {
+                    [name: string]: unknown;
+                };
+                content: {
+                    "*/*": components["schemas"]["TimelineEventView"];
+                };
+            };
+        };
+    };
+    update: {
+        parameters: {
+            query?: never;
+            header?: never;
+            path: {
+                id: string;
+            };
+            cookie?: never;
+        };
+        requestBody: {
+            content: {
+                "application/json": components["schemas"]["TimelineEventRequest"];
+            };
+        };
+        responses: {
+            /** @description OK */
+            200: {
+                headers: {
+                    [name: string]: unknown;
+                };
+                content: {
+                    "*/*": components["schemas"]["TimelineEventView"];
+                };
+            };
+        };
+    };
+    delete: {
+        parameters: {
+            query?: never;
+            header?: never;
+            path: {
+                id: string;
+            };
+            cookie?: never;
+        };
+        requestBody?: never;
+        responses: {
+            /** @description OK */
+            200: {
+                headers: {
+                    [name: string]: unknown;
+                };
+                content?: never;
+            };
+        };
+    };
     updateTag: {
         parameters: {
             query?: never;
@@ -3325,6 +3522,30 @@ export interface operations {
             };
         };
     };
+    create: {
+        parameters: {
+            query?: never;
+            header?: never;
+            path?: never;
+            cookie?: never;
+        };
+        requestBody: {
+            content: {
+                "application/json": components["schemas"]["TimelineEventRequest"];
+            };
+        };
+        responses: {
+            /** @description Created */
+            201: {
+                headers: {
+                    [name: string]: unknown;
+                };
+                content: {
+                    "*/*": components["schemas"]["TimelineEventView"];
+                };
+            };
+        };
+    };
     mergeTag: {
         parameters: {
             query?: never;
@@ -3754,7 +3975,7 @@ export interface operations {
             };
         };
     };
-    create: {
+    create_1: {
         parameters: {
             query?: never;
             header?: never;
@@ -4480,7 +4701,7 @@ export interface operations {
             };
         };
     };
-    delete: {
+    delete_1: {
         parameters: {
             query?: never;
             header?: never;
@@ -4500,7 +4721,7 @@ export interface operations {
             };
         };
     };
-    update: {
+    update_1: {
         parameters: {
             query?: never;
             header?: never;
@@ -4820,6 +5041,32 @@ export interface operations {
             };
         };
     };
+    getTimeline: {
+        parameters: {
+            query?: {
+                personId?: string;
+                generation?: number;
+                type?: "PERSONAL" | "HISTORICAL";
+                fromYear?: number;
+                toYear?: number;
+            };
+            header?: never;
+            path?: never;
+            cookie?: never;
+        };
+        requestBody?: never;
+        responses: {
+            /** @description OK */
+            200: {
+                headers: {
+                    [name: string]: unknown;
+                };
+                content: {
+                    "*/*": components["schemas"]["TimelineDTO"];
+                };
+            };
+        };
+    };
     searchTags: {
         parameters: {
             query?: {

frontend/src/lib/messages.spec.ts

@@ -40,4 +40,32 @@ describe('message key parity', () => {
 		expect(es).toHaveProperty('layout_menu_open');
 		expect(es).toHaveProperty('layout_menu_close');
 	});
+
+	// REQ-024: the timeline layer/life-event labels feed sr-only / aria text, so
+	// they are localized per locale (the original German-only MVP decision was
+	// reversed for accessibility). Pin the values so en/es can never silently
+	// drift back to the German source strings.
+	it('timeline layer/derived labels are localized per locale (REQ-024)', () => {
+		expect(de).toMatchObject({
+			timeline_layer_world: 'Weltgeschehen',
+			timeline_layer_family: 'Familie',
+			timeline_derived_birth: 'Geburt',
+			timeline_derived_death: 'Tod',
+			timeline_derived_marriage: 'Heirat'
+		});
+		expect(en).toMatchObject({
+			timeline_layer_world: 'World events',
+			timeline_layer_family: 'Family',
+			timeline_derived_birth: 'Birth',
+			timeline_derived_death: 'Death',
+			timeline_derived_marriage: 'Marriage'
+		});
+		expect(es).toMatchObject({
+			timeline_layer_world: 'Acontecimientos mundiales',
+			timeline_layer_family: 'Familia',
+			timeline_derived_birth: 'Nacimiento',
+			timeline_derived_death: 'Fallecimiento',
+			timeline_derived_marriage: 'Matrimonio'
+		});
+	});
 });

frontend/src/lib/shared/README.md

@@ -15,11 +15,13 @@ If any condition fails, the file belongs in the domain folder of its primary con
 ## What this folder owns
 
 | Sub-folder / file             | Purpose                                                                                                                                                                                                                                            |
-| ----------------- | ----------------------------------------------------------------------------------------------------------------------------------- |
+| ----------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | `api.server.ts`               | Typed `openapi-fetch` client factory — the standard entry point for all backend API calls in server-side load functions and actions                                                                                                                |
 | `errors.ts`                   | Mirror of the backend `ErrorCode` enum + `getErrorMessage()` → Paraglide i18n key mapping                                                                                                                                                          |
 | `types.ts`                    | Cross-domain TypeScript interfaces                                                                                                                                                                                                                 |
 | `utils.ts`                    | Pure utility functions (date formatting, sorting, debounce)                                                                                                                                                                                        |
+| `utils/monthBuckets.ts`       | Pure month-bucket math (boundaries, sequences, gap-fill, year aggregation, axis ticks) shared by the `document/` density chart and the `timeline/` density strip — moved up from `document/timeline.ts` so `timeline/` need not import `document/` |
+| `primitives/Sparkline.svelte` | Fixed-series bar sparkline (one bar per value) — used by the timeline density strip                                                                                                                                                                |
 | `relativeTime.ts`             | Human-relative time formatting (`"2 days ago"`)                                                                                                                                                                                                    |
 | `primitives/`                 | Generic UI components: `BackButton.svelte`, form inputs, pagination, layout shells                                                                                                                                                                 |
 | `discussion/`                 | Comment/mention editor shared by `document/` and `geschichte/`                                                                                                                                                                                     |

frontend/src/lib/shared/errors.ts

@@ -56,6 +56,9 @@ export type ErrorCode =
 	| 'GESCHICHTE_TYPE_IMMUTABLE'
 	| 'GESCHICHTE_TITLE_TOO_LONG'
 	| 'GESCHICHTE_INTRO_TOO_LONG'
+	| 'TIMELINE_EVENT_NOT_FOUND'
+	| 'TIMELINE_EVENT_CONFLICT'
+	| 'TIMELINE_TITLE_TOO_LONG'
 	| 'INVALID_CREDENTIALS'
 	| 'SESSION_EXPIRED'
 	| 'MISSING_CREDENTIALS'
@@ -66,6 +69,7 @@ export type ErrorCode =
 	| 'VALIDATION_ERROR'
 	| 'BATCH_TOO_LARGE'
 	| 'BULK_EDIT_TOO_MANY_IDS'
+	| 'CONFLICT'
 	| 'INTERNAL_ERROR';
 
 export interface BackendError {
@@ -194,6 +198,12 @@ export function getErrorMessage(code: ErrorCode | string | undefined): string {
 			return m.error_geschichte_title_too_long();
 		case 'GESCHICHTE_INTRO_TOO_LONG':
 			return m.error_geschichte_intro_too_long();
+		case 'TIMELINE_EVENT_NOT_FOUND':
+			return m.error_timeline_event_not_found();
+		case 'TIMELINE_EVENT_CONFLICT':
+			return m.error_timeline_event_conflict();
+		case 'TIMELINE_TITLE_TOO_LONG':
+			return m.error_timeline_title_too_long();
 		case 'INVALID_CREDENTIALS':
 			return m.error_invalid_credentials();
 		case 'SESSION_EXPIRED':
@@ -214,6 +224,8 @@ export function getErrorMessage(code: ErrorCode | string | undefined): string {
 			return m.error_batch_too_large();
 		case 'BULK_EDIT_TOO_MANY_IDS':
 			return m.error_bulk_edit_too_many_ids();
+		case 'CONFLICT':
+			return m.error_conflict();
 		default:
 			return m.error_internal_error();
 	}

frontend/src/lib/shared/primitives/Sparkline.svelte

@@ -0,0 +1,38 @@
+<script lang="ts">
+/**
+ * A minimal fixed-series bar sparkline: one bar per value, heights scaled to the
+ * largest value. Presentational only — callers supply the already-bucketed
+ * counts. Used by the timeline density strip; reusable by the document chart.
+ */
+let {
+	values,
+	label,
+	class: className = ''
+}: { values: number[]; label?: string; class?: string } = $props();
+
+const max = $derived(Math.max(1, ...values));
+
+// Empty buckets keep a faint floor so the series reads as a continuous axis
+// rather than disappearing to nothing.
+const MIN_HEIGHT_PCT = 4;
+
+function heightPct(value: number): number {
+	if (value <= 0) return MIN_HEIGHT_PCT;
+	return Math.max(MIN_HEIGHT_PCT, (value / max) * 100);
+}
+</script>
+
+<div
+	class="flex h-8 items-end gap-[1.5px] {className}"
+	role="img"
+	aria-label={label}
+	aria-hidden={label ? undefined : 'true'}
+>
+	{#each values as value, i (i)}
+		<div
+			data-testid="sparkline-bar"
+			class="flex-1 rounded-[1px] bg-brand-mint"
+			style="height: {heightPct(value)}%"
+		></div>
+	{/each}
+</div>

frontend/src/lib/shared/primitives/Sparkline.svelte.spec.ts

@@ -0,0 +1,28 @@
+import { describe, it, expect, afterEach } from 'vitest';
+import { cleanup, render } from 'vitest-browser-svelte';
+import Sparkline from './Sparkline.svelte';
+
+afterEach(() => cleanup());
+
+describe('Sparkline', () => {
+	it('renders one bar per value', () => {
+		render(Sparkline, { values: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11] });
+		const bars = document.querySelectorAll('[data-testid="sparkline-bar"]');
+		expect(bars).toHaveLength(12);
+	});
+
+	it('scales bar heights relative to the largest value', () => {
+		render(Sparkline, { values: [5, 10, 0] });
+		const bars = document.querySelectorAll<HTMLElement>('[data-testid="sparkline-bar"]');
+		const h = (i: number) => parseFloat(bars[i].style.height);
+		// 10 is the max → tallest; 5 is half of the max's height; 0 is the shortest.
+		expect(h(1)).toBeGreaterThan(h(0));
+		expect(h(0)).toBeGreaterThan(h(2));
+	});
+
+	it('exposes an accessible label when provided', () => {
+		render(Sparkline, { values: [1, 2, 3], label: 'Monatsdichte' });
+		const img = document.querySelector('[role="img"]');
+		expect(img?.getAttribute('aria-label')).toBe('Monatsdichte');
+	});
+});

frontend/src/lib/shared/utils/documentDate.ts

@@ -4,6 +4,13 @@ import { m } from '$lib/paraglide/messages.js';
 /**
  * Precision of a document's date — mirrors the backend {@code DatePrecision} enum
  * and the import normalizer's seven values verbatim.
+ *
+ * DRIFT RISK: this is a hand-maintained mirror of the Java {@code DatePrecision}
+ * enum, NOT an OpenAPI-generated type. It must be updated manually whenever the
+ * Java enum changes, and must NOT be migrated to the generated API type — the
+ * generated enum is request/response-shaped, while this drives the shared
+ * client-side formatter (used by both documents and the timeline façade). Keep
+ * the two in lockstep by hand.
  */
 export type DatePrecision = 'DAY' | 'MONTH' | 'SEASON' | 'YEAR' | 'RANGE' | 'APPROX' | 'UNKNOWN';
 

frontend/src/lib/shared/utils/monthBuckets.spec.ts

@@ -0,0 +1,267 @@
+import { describe, it, expect } from 'vitest';
+import {
+	monthBoundaryFrom,
+	monthBoundaryTo,
+	buildMonthSequence,
+	fillDensityGaps,
+	aggregateToYears,
+	selectionBoundaryFrom,
+	selectionBoundaryTo,
+	clipBucketsToRange,
+	tickIndicesFor,
+	formatTickLabel
+} from './monthBuckets';
+
+describe('monthBoundaryFrom', () => {
+	it('returns the first day of the given month', () => {
+		expect(monthBoundaryFrom('1915-08')).toBe('1915-08-01');
+	});
+
+	it('handles January', () => {
+		expect(monthBoundaryFrom('1920-01')).toBe('1920-01-01');
+	});
+});
+
+describe('monthBoundaryTo', () => {
+	it('returns the last day of a 31-day month', () => {
+		expect(monthBoundaryTo('1915-08')).toBe('1915-08-31');
+	});
+
+	it('returns the last day of a 30-day month', () => {
+		expect(monthBoundaryTo('1915-04')).toBe('1915-04-30');
+	});
+
+	it('returns 28 for February in a non-leap year', () => {
+		expect(monthBoundaryTo('1915-02')).toBe('1915-02-28');
+	});
+
+	it('returns 29 for February in a leap year', () => {
+		expect(monthBoundaryTo('1916-02')).toBe('1916-02-29');
+	});
+});
+
+describe('buildMonthSequence', () => {
+	it('returns a single month when min and max are in the same month', () => {
+		expect(buildMonthSequence('1915-08-03', '1915-08-22')).toEqual(['1915-08']);
+	});
+
+	it('returns months from minDate through maxDate inclusive', () => {
+		expect(buildMonthSequence('1915-08-03', '1915-11-15')).toEqual([
+			'1915-08',
+			'1915-09',
+			'1915-10',
+			'1915-11'
+		]);
+	});
+
+	it('crosses year boundaries correctly', () => {
+		expect(buildMonthSequence('1915-11-30', '1916-02-01')).toEqual([
+			'1915-11',
+			'1915-12',
+			'1916-01',
+			'1916-02'
+		]);
+	});
+
+	it('returns empty array when minDate or maxDate is null', () => {
+		expect(buildMonthSequence(null, '1915-08-01')).toEqual([]);
+		expect(buildMonthSequence('1915-08-01', null)).toEqual([]);
+		expect(buildMonthSequence(null, null)).toEqual([]);
+	});
+});
+
+describe('fillDensityGaps', () => {
+	it('returns empty array when minDate or maxDate is null', () => {
+		expect(fillDensityGaps([], null, null)).toEqual([]);
+	});
+
+	it('preserves existing buckets and adds zero-count buckets for missing months', () => {
+		const buckets = [
+			{ month: '1915-08', count: 5 },
+			{ month: '1915-11', count: 2 }
+		];
+
+		const result = fillDensityGaps(buckets, '1915-08-03', '1915-11-30');
+
+		expect(result).toEqual([
+			{ month: '1915-08', count: 5 },
+			{ month: '1915-09', count: 0 },
+			{ month: '1915-10', count: 0 },
+			{ month: '1915-11', count: 2 }
+		]);
+	});
+
+	it('returns all-zero sequence when buckets array is empty', () => {
+		const result = fillDensityGaps([], '1915-08-03', '1915-10-15');
+
+		expect(result).toEqual([
+			{ month: '1915-08', count: 0 },
+			{ month: '1915-09', count: 0 },
+			{ month: '1915-10', count: 0 }
+		]);
+	});
+
+	it('keeps results sorted chronologically even when buckets arrive out of order', () => {
+		const buckets = [
+			{ month: '1915-10', count: 3 },
+			{ month: '1915-08', count: 1 }
+		];
+
+		const result = fillDensityGaps(buckets, '1915-08-01', '1915-10-31');
+
+		expect(result.map((b) => b.month)).toEqual(['1915-08', '1915-09', '1915-10']);
+	});
+});
+
+describe('aggregateToYears', () => {
+	it('returns empty array for empty input', () => {
+		expect(aggregateToYears([])).toEqual([]);
+	});
+
+	it('sums counts within the same year', () => {
+		const result = aggregateToYears([
+			{ month: '1915-08', count: 5 },
+			{ month: '1915-09', count: 2 },
+			{ month: '1915-10', count: 8 }
+		]);
+		expect(result).toEqual([{ month: '1915', count: 15 }]);
+	});
+
+	it('produces one bucket per distinct year, sorted chronologically', () => {
+		const result = aggregateToYears([
+			{ month: '1916-01', count: 3 },
+			{ month: '1915-08', count: 5 },
+			{ month: '1916-04', count: 7 },
+			{ month: '1914-12', count: 1 }
+		]);
+		expect(result).toEqual([
+			{ month: '1914', count: 1 },
+			{ month: '1915', count: 5 },
+			{ month: '1916', count: 10 }
+		]);
+	});
+});
+
+describe('clipBucketsToRange', () => {
+	const buckets = [
+		{ month: '1915-08', count: 5 },
+		{ month: '1915-09', count: 2 },
+		{ month: '1915-10', count: 8 },
+		{ month: '1915-11', count: 3 }
+	];
+
+	it('returns the original buckets when range bounds are null', () => {
+		expect(clipBucketsToRange(buckets, null, null)).toBe(buckets);
+	});
+
+	it('keeps only buckets whose month falls within the range', () => {
+		expect(clipBucketsToRange(buckets, '1915-09-01', '1915-10-31')).toEqual([
+			{ month: '1915-09', count: 2 },
+			{ month: '1915-10', count: 8 }
+		]);
+	});
+
+	it('returns an empty array when the range excludes everything', () => {
+		expect(clipBucketsToRange(buckets, '1916-01-01', '1916-12-31')).toEqual([]);
+	});
+
+	it('treats partial dates correctly when bounds cross month boundaries', () => {
+		expect(clipBucketsToRange(buckets, '1915-09-15', '1915-10-15')).toEqual([
+			{ month: '1915-09', count: 2 },
+			{ month: '1915-10', count: 8 }
+		]);
+	});
+});
+
+describe('selectionBoundaryFrom / To', () => {
+	it('handles month labels (YYYY-MM)', () => {
+		expect(selectionBoundaryFrom('1915-08')).toBe('1915-08-01');
+		expect(selectionBoundaryTo('1915-08')).toBe('1915-08-31');
+	});
+
+	it('handles year labels (YYYY)', () => {
+		expect(selectionBoundaryFrom('1915')).toBe('1915-01-01');
+		expect(selectionBoundaryTo('1915')).toBe('1915-12-31');
+	});
+});
+
+describe('tickIndicesFor', () => {
+	it('returns no indices for an empty bucket list', () => {
+		expect(tickIndicesFor([])).toEqual([]);
+	});
+
+	it('picks years divisible by 25 when the year span exceeds 120', () => {
+		const buckets = Array.from({ length: 150 }, (_, i) => ({
+			month: String(1875 + i),
+			count: 1
+		}));
+		const ticks = tickIndicesFor(buckets);
+		const labels = ticks.map((i) => buckets[i].month);
+		expect(labels).toEqual(['1875', '1900', '1925', '1950', '1975', '2000']);
+	});
+
+	it('picks years divisible by 10 for medium ranges (~50 years)', () => {
+		const buckets = Array.from({ length: 50 }, (_, i) => ({
+			month: String(1900 + i),
+			count: 1
+		}));
+		const ticks = tickIndicesFor(buckets);
+		const labels = ticks.map((i) => buckets[i].month);
+		expect(labels).toEqual(['1900', '1910', '1920', '1930', '1940']);
+	});
+
+	it('picks January boundaries for long month ranges', () => {
+		const buckets = [
+			{ month: '1914-08', count: 1 },
+			{ month: '1914-09', count: 1 },
+			{ month: '1914-10', count: 1 },
+			{ month: '1914-11', count: 1 },
+			{ month: '1914-12', count: 1 },
+			{ month: '1915-01', count: 1 },
+			{ month: '1915-02', count: 1 },
+			{ month: '1915-03', count: 1 },
+			{ month: '1915-04', count: 1 },
+			{ month: '1915-05', count: 1 },
+			{ month: '1915-06', count: 1 },
+			{ month: '1915-07', count: 1 },
+			{ month: '1915-08', count: 1 },
+			{ month: '1915-09', count: 1 },
+			{ month: '1915-10', count: 1 },
+			{ month: '1915-11', count: 1 },
+			{ month: '1915-12', count: 1 },
+			{ month: '1916-01', count: 1 },
+			{ month: '1916-02', count: 1 }
+		];
+		const ticks = tickIndicesFor(buckets);
+		expect(ticks.map((i) => buckets[i].month)).toEqual(['1915-01', '1916-01']);
+	});
+
+	it('falls back to evenly spaced ticks for short month ranges (12 months)', () => {
+		const buckets = Array.from({ length: 12 }, (_, i) => ({
+			month: `1905-${String(i + 1).padStart(2, '0')}`,
+			count: 1
+		}));
+		const ticks = tickIndicesFor(buckets);
+		expect(ticks.length).toBeGreaterThanOrEqual(5);
+		expect(ticks.length).toBeLessThanOrEqual(7);
+		expect(ticks[0]).toBe(0);
+	});
+});
+
+describe('formatTickLabel', () => {
+	it('returns the year string unchanged for year labels', () => {
+		expect(formatTickLabel('1905', 'en-US')).toBe('1905');
+	});
+
+	it('formats month labels with the year by default', () => {
+		const result = formatTickLabel('1905-06', 'en-US');
+		expect(result).toMatch(/Jun/);
+		expect(result).toMatch(/1905/);
+	});
+
+	it('omits the year when omitYear is true', () => {
+		const result = formatTickLabel('1905-06', 'en-US', true);
+		expect(result).toMatch(/Jun/);
+		expect(result).not.toMatch(/1905/);
+	});
+});

frontend/src/lib/shared/utils/monthBuckets.ts

@@ -0,0 +1,163 @@
+import type { components } from '$lib/generated/api';
+
+/**
+ * Pure month-bucket math shared by the document density chart (`lib/document/`)
+ * and the global timeline strip (`lib/timeline/`). Reuses the generated
+ * `MonthBucket` schema type so both surfaces stay coupled to the backend shape.
+ * No I/O, no DOM — relocated here so `lib/timeline/` never imports `lib/document/`.
+ */
+export type MonthBucket = components['schemas']['MonthBucket'];
+
+export function monthBoundaryFrom(yearMonth: string): string {
+	return `${yearMonth}-01`;
+}
+
+export function monthBoundaryTo(yearMonth: string): string {
+	const [year, month] = yearMonth.split('-').map(Number);
+	// Day 0 of `month + 1` rolls back to the last day of `month` — so passing
+	// `month` (1-indexed) into `Date.UTC(year, month, 0)` lands on the last day
+	// of that month. Handles 28/29/30/31 and leap years without a lookup table.
+	const lastDay = new Date(Date.UTC(year, month, 0)).getUTCDate();
+	return `${yearMonth}-${String(lastDay).padStart(2, '0')}`;
+}
+
+export function buildMonthSequence(minDate: string | null, maxDate: string | null): string[] {
+	if (!minDate || !maxDate) return [];
+
+	const [minY, minM] = minDate.split('-').map(Number);
+	const [maxY, maxM] = maxDate.split('-').map(Number);
+
+	const sequence: string[] = [];
+	let year = minY;
+	let month = minM;
+
+	while (year < maxY || (year === maxY && month <= maxM)) {
+		sequence.push(`${year}-${String(month).padStart(2, '0')}`);
+		month += 1;
+		if (month > 12) {
+			month = 1;
+			year += 1;
+		}
+	}
+
+	return sequence;
+}
+
+export function fillDensityGaps(
+	buckets: MonthBucket[],
+	minDate: string | null,
+	maxDate: string | null
+): MonthBucket[] {
+	const sequence = buildMonthSequence(minDate, maxDate);
+	if (sequence.length === 0) return [];
+
+	const counts = new Map(buckets.map((b) => [b.month, b.count]));
+	return sequence.map((month) => ({ month, count: counts.get(month) ?? 0 }));
+}
+
+/**
+ * Returns only the month buckets whose YYYY-MM falls inside the provided
+ * `[fromInclusive, toInclusive]` ISO date range. When either bound is null the
+ * input array is returned unchanged. Used by the timeline's zoom-in tool to
+ * narrow the visible bars without refetching data.
+ *
+ * @internal Sole call site is `TimelineDensityFilter.svelte`. Exported so the
+ * unit suite (`monthBuckets.spec.ts`) can pin the boundary semantics directly.
+ */
+export function clipBucketsToRange(
+	buckets: MonthBucket[],
+	fromInclusive: string | null,
+	toInclusive: string | null
+): MonthBucket[] {
+	if (!fromInclusive || !toInclusive) return buckets;
+	const fromMonth = fromInclusive.slice(0, 7);
+	const toMonth = toInclusive.slice(0, 7);
+	return buckets.filter((b) => b.month >= fromMonth && b.month <= toMonth);
+}
+
+/**
+ * Aggregates month-granular buckets into one entry per year. Month strings are
+ * truncated to "YYYY" and counts are summed. Used when the date span is too
+ * long for month-granular bars to render at a clickable size.
+ */
+export function aggregateToYears(buckets: MonthBucket[]): MonthBucket[] {
+	const totals = new Map<string, number>();
+	for (const b of buckets) {
+		const year = b.month.slice(0, 4);
+		totals.set(year, (totals.get(year) ?? 0) + b.count);
+	}
+	return Array.from(totals.entries())
+		.map(([year, count]) => ({ month: year, count }))
+		.sort((a, b) => a.month.localeCompare(b.month));
+}
+
+/**
+ * Boundary helpers for selection. Accept either "YYYY-MM" (month) or "YYYY"
+ * (year) and return the matching LocalDate string.
+ */
+export function selectionBoundaryFrom(label: string): string {
+	return label.length === 4 ? `${label}-01-01` : `${label}-01`;
+}
+
+export function selectionBoundaryTo(label: string): string {
+	if (label.length === 4) return `${label}-12-31`;
+	return monthBoundaryTo(label);
+}
+
+/**
+ * Picks bucket indices that should get an X-axis tick label. The strategy adapts
+ * to whether bars are years or months and how many are visible:
+ *  - Year bars: pick years divisible by a step that scales with range length
+ *    (every 25 yrs for >120 bars, every 20 / 10 / 5 / 1 below).
+ *  - Month bars: prefer January boundaries (year breaks). For ≤18 bars (e.g.
+ *    one year zoomed in to months), fall back to evenly spaced ticks so we
+ *    show ~6 labels even when no January boundary exists.
+ */
+export function tickIndicesFor(filled: MonthBucket[]): number[] {
+	if (filled.length === 0) return [];
+	const isYearMode = filled[0].month.length === 4;
+	const indices: number[] = [];
+
+	if (isYearMode) {
+		const years = filled.length;
+		const step =
+			years > 120 ? 25 : years > 60 ? 20 : years > 30 ? 10 : years > 12 ? 5 : years > 6 ? 2 : 1;
+		for (let i = 0; i < filled.length; i++) {
+			const year = parseInt(filled[i].month, 10);
+			if (year % step === 0) indices.push(i);
+		}
+		return indices;
+	}
+
+	if (filled.length <= 18) {
+		const step = Math.max(1, Math.round(filled.length / 6));
+		for (let i = 0; i < filled.length; i += step) indices.push(i);
+		return indices;
+	}
+
+	// Long month range — pick January boundaries (year breaks).
+	for (let i = 0; i < filled.length; i++) {
+		if (filled[i].month.endsWith('-01')) indices.push(i);
+	}
+	// Fallback if there's no January in the visible range (rare): even spacing.
+	if (indices.length === 0) {
+		const step = Math.max(1, Math.round(filled.length / 6));
+		for (let i = 0; i < filled.length; i += step) indices.push(i);
+	}
+	return indices;
+}
+
+/**
+ * Formats a bucket month label ("YYYY" or "YYYY-MM") for the X-axis. When
+ * `omitYear` is true the year is dropped so a 12-month zoomed view reads as
+ * "Jan", "Feb", … without repetition.
+ */
+export function formatTickLabel(label: string, locale?: string, omitYear = false): string {
+	if (label.length === 4) return label;
+	const [yearStr, monthStr] = label.split('-');
+	const date = new Date(parseInt(yearStr, 10), parseInt(monthStr, 10) - 1, 1);
+	const opts: Intl.DateTimeFormatOptions = omitYear
+		? { month: 'short' }
+		: { month: 'short', year: 'numeric' };
+	return new Intl.DateTimeFormat(locale, opts).format(date);
+}

frontend/src/lib/timeline/EventPill.svelte

@@ -0,0 +1,59 @@
+<script lang="ts">
+import * as m from '$lib/paraglide/messages.js';
+import { getAccentConfig } from './eventCardConfig';
+import { timelineDateLabel } from './dateLabel';
+import type { components } from '$lib/generated/api';
+
+type TimelineEntryDTO = components['schemas']['TimelineEntryDTO'];
+
+/**
+ * Centered axis pill for a derived life-event or a curated PERSONAL event
+ * (REQ-007/008). The glyph is wrapped aria-hidden with an sr-only label sibling
+ * (REQ-018). An edit affordance shows only for a curated event with an eventId
+ * (never derived, never null — REQ-008).
+ */
+let { entry }: { entry: TimelineEntryDTO } = $props();
+
+const config = $derived(getAccentConfig(entry));
+const dateLabel = $derived(timelineDateLabel(entry.eventDate, entry.precision, entry.eventDateEnd));
+const canEdit = $derived(!entry.derived && entry.eventId != null);
+</script>
+
+<div class="flex justify-center">
+	<div
+		class="inline-flex items-center gap-2 rounded-full bg-surface px-3 py-1 shadow-sm {config.accent ===
+		'curated'
+			? 'border-2 border-brand-mint'
+			: 'border border-brand-navy'}"
+	>
+		<span
+			class="flex h-7 w-7 shrink-0 items-center justify-center rounded-full {config.accent ===
+			'curated'
+				? 'bg-brand-mint text-brand-navy'
+				: 'bg-brand-navy text-brand-mint'}"
+		>
+			<span aria-hidden="true">{config.glyph}</span>
+			<span class="sr-only">{config.label}</span>
+		</span>
+		<span class="text-left">
+			{#if entry.title}
+				<span class="block font-serif text-sm font-bold whitespace-pre-line text-brand-navy"
+					>{entry.title}</span
+				>
+			{/if}
+			{#if dateLabel}
+				<span class="block font-sans text-xs text-ink-3">{dateLabel}</span>
+			{/if}
+		</span>
+		{#if canEdit}
+			<a
+				data-testid="event-edit"
+				href="/zeitstrahl/events/{entry.eventId}/edit"
+				class="ml-1 rounded-sm px-1 font-sans text-xs text-ink-3 hover:text-brand-navy focus:outline-none focus-visible:ring-2 focus-visible:ring-brand-navy"
+			>
+				<span aria-hidden="true">✎</span>
+				<span class="sr-only">{m.btn_edit()}</span>
+			</a>
+		{/if}
+	</div>
+</div>

frontend/src/lib/timeline/EventPill.svelte.spec.ts

@@ -0,0 +1,90 @@
+import { describe, it, expect, afterEach } from 'vitest';
+import { cleanup, render } from 'vitest-browser-svelte';
+import EventPill from './EventPill.svelte';
+import { makeEntry } from './test-factories';
+
+afterEach(() => cleanup());
+
+const EVENT_ID = '33333333-3333-3333-3333-333333333333';
+
+function derived(derivedType: 'BIRTH' | 'DEATH' | 'MARRIAGE', title: string) {
+	return makeEntry({
+		kind: 'EVENT',
+		derived: true,
+		derivedType,
+		title,
+		senderName: '',
+		receiverName: '',
+		precision: 'YEAR',
+		eventDate: '1914-01-01',
+		documentId: undefined
+	});
+}
+
+describe('EventPill', () => {
+	it('renders a derived marriage as ⚭ + "Heirat" + title (REQ-007)', () => {
+		render(EventPill, { entry: derived('MARRIAGE', 'Heirat: Karl & Elfriede') });
+		expect(document.body.textContent).toContain('⚭');
+		expect(document.body.textContent).toContain('Heirat');
+		expect(document.body.textContent).toContain('Heirat: Karl & Elfriede');
+	});
+
+	it('renders a derived birth as * + "Geburt" (REQ-007)', () => {
+		render(EventPill, { entry: derived('BIRTH', 'Geburt: Hans') });
+		expect(document.body.textContent).toContain('*');
+		expect(document.body.textContent).toContain('Geburt');
+	});
+
+	it('renders a derived death as † + "Tod" (REQ-007)', () => {
+		render(EventPill, { entry: derived('DEATH', 'Tod: Karl') });
+		expect(document.body.textContent).toContain('†');
+		expect(document.body.textContent).toContain('Tod');
+	});
+
+	it('wraps the glyph aria-hidden with an sr-only label sibling (REQ-018)', () => {
+		render(EventPill, { entry: derived('BIRTH', 'Geburt: Hans') });
+		const hidden = document.querySelector('[aria-hidden="true"]');
+		expect(hidden?.textContent).toBe('*');
+		const srOnly = document.querySelector('.sr-only');
+		expect(srOnly?.textContent).toBe('Geburt');
+	});
+
+	it('shows an edit affordance for a curated PERSONAL event with an eventId (REQ-008)', () => {
+		render(EventPill, {
+			entry: makeEntry({
+				kind: 'EVENT',
+				derived: false,
+				type: 'PERSONAL',
+				eventId: EVENT_ID,
+				title: 'Auswanderung',
+				senderName: '',
+				receiverName: '',
+				documentId: undefined
+			})
+		});
+		const edit = document.querySelector('[data-testid="event-edit"]') as HTMLAnchorElement | null;
+		expect(edit).not.toBeNull();
+		expect(edit?.getAttribute('href')).toContain(EVENT_ID);
+	});
+
+	it('shows no edit affordance when eventId is null (REQ-008)', () => {
+		render(EventPill, {
+			entry: makeEntry({
+				kind: 'EVENT',
+				derived: false,
+				type: 'PERSONAL',
+				eventId: undefined,
+				title: 'Auswanderung',
+				senderName: '',
+				receiverName: '',
+				documentId: undefined
+			})
+		});
+		expect(document.querySelector('[data-testid="event-edit"]')).toBeNull();
+	});
+
+	it('shows no edit affordance for a derived event (REQ-008)', () => {
+		render(EventPill, { entry: derived('MARRIAGE', 'Heirat') });
+		expect(document.querySelector('[data-testid="event-edit"]')).toBeNull();
+	});
+});

frontend/src/lib/timeline/GapSpan.svelte

@@ -0,0 +1,20 @@
+<script lang="ts">
+import * as m from '$lib/paraglide/messages.js';
+
+/**
+ * A folded run of fully-empty interior years (REQ-015), rendered as a thin
+ * dashed span so the scroll stays oriented. Collapses to a single year when the
+ * run has length 1.
+ */
+let { from, to }: { from: number; to: number } = $props();
+
+const yearLabel = $derived(from === to ? `${from}` : `${from}–${to}`);
+</script>
+
+<div
+	class="mx-auto my-2 flex max-w-md items-center gap-2 rounded-full border border-dashed border-line bg-canvas px-4 py-1 font-sans text-xs text-ink-3"
+>
+	<span class="h-px flex-1 bg-line"></span>
+	<span><span class="font-serif text-ink-2">{yearLabel}</span> · {m.timeline_gap_empty()}</span>
+	<span class="h-px flex-1 bg-line"></span>
+</div>

frontend/src/lib/timeline/GapSpan.svelte.spec.ts

@@ -0,0 +1,20 @@
+import { describe, it, expect, afterEach } from 'vitest';
+import { cleanup, render } from 'vitest-browser-svelte';
+import GapSpan from './GapSpan.svelte';
+
+afterEach(() => cleanup());
+
+describe('GapSpan', () => {
+	it('renders a multi-year empty run as "{from}–{to} · keine Einträge" (REQ-015)', () => {
+		render(GapSpan, { from: 1910, to: 1914 });
+		expect(document.body.textContent).toContain('1910–1914');
+		expect(document.body.textContent).toContain('keine Einträge');
+	});
+
+	it('renders a single empty year as "{year} · keine Einträge" (REQ-015)', () => {
+		render(GapSpan, { from: 1912, to: 1912 });
+		expect(document.body.textContent).toContain('1912');
+		expect(document.body.textContent).not.toContain('1912–1912');
+		expect(document.body.textContent).toContain('keine Einträge');
+	});
+});

frontend/src/lib/timeline/LetterCard.svelte

@@ -0,0 +1,44 @@
+<script lang="ts">
+import * as m from '$lib/paraglide/messages.js';
+import { timelineDateLabel } from './dateLabel';
+import type { components } from '$lib/generated/api';
+
+type TimelineEntryDTO = components['schemas']['TimelineEntryDTO'];
+
+/**
+ * A single archive letter on the timeline: sender → receiver, title, and a
+ * precision-aware date chip, linking to the document. Names/titles are
+ * OCR/import-derived — rendered via default `{...}` escaping with
+ * `whitespace-pre-line` for line breaks (REQ-021); never the raw-HTML directive.
+ */
+let { entry }: { entry: TimelineEntryDTO } = $props();
+
+const dateLabel = $derived(timelineDateLabel(entry.eventDate, entry.precision, entry.eventDateEnd));
+const sender = $derived(entry.senderName === '' ? m.timeline_unknown_person() : entry.senderName);
+const receiver = $derived(
+	entry.receiverName === '' ? m.timeline_unknown_person() : entry.receiverName
+);
+</script>
+
+<!-- Box layout inline (not just utility classes) so the 44px touch target holds
+     even before the stylesheet loads — an <a> is inline by default and would
+     ignore min-height otherwise. WCAG 2.5.5 (REQ-020). -->
+<a
+	href="/documents/{entry.documentId}"
+	style="display: flex; flex-direction: column; justify-content: center; min-height: 44px"
+	class="rounded-sm border border-l-[3px] border-line border-l-brand-mint bg-surface px-3 py-2 shadow-sm transition-colors hover:border-brand-mint focus:outline-none focus-visible:ring-2 focus-visible:ring-brand-navy"
+>
+	{#if entry.title}
+		<span class="font-serif text-sm font-bold break-words whitespace-pre-line text-ink"
+			>{entry.title}</span
+		>
+	{/if}
+	<span class="mt-0.5 font-sans text-xs break-words text-ink-3">
+		<span class="font-serif whitespace-pre-line">{sender}</span>
+		<span aria-hidden="true">→</span>
+		<span class="font-serif whitespace-pre-line">{receiver}</span>
+		{#if dateLabel}
+			<span data-testid="letter-date"> · {dateLabel}</span>
+		{/if}
+	</span>
+</a>

frontend/src/lib/timeline/LetterCard.svelte.spec.ts

@@ -0,0 +1,58 @@
+import { describe, it, expect, afterEach } from 'vitest';
+import { cleanup, render } from 'vitest-browser-svelte';
+import LetterCard from './LetterCard.svelte';
+import { timelineDateLabel } from './dateLabel';
+import { makeEntry } from './test-factories';
+
+afterEach(() => cleanup());
+
+const DOC_ID = '22222222-2222-2222-2222-222222222222';
+
+describe('LetterCard', () => {
+	it('renders sender, receiver, and title', () => {
+		render(LetterCard, {
+			entry: makeEntry({ senderName: 'Karl', receiverName: 'Elfriede', title: 'Feldpost' })
+		});
+		expect(document.body.textContent).toContain('Karl');
+		expect(document.body.textContent).toContain('Elfriede');
+		expect(document.body.textContent).toContain('Feldpost');
+	});
+
+	it('renders the precision date exactly as timelineDateLabel returns (REQ-013)', () => {
+		const entry = makeEntry({ eventDate: '1915-06-15', precision: 'MONTH' });
+		const expected = timelineDateLabel(entry.eventDate, entry.precision, entry.eventDateEnd);
+		expect(expected).toBeTruthy();
+		render(LetterCard, { entry });
+		expect(document.body.textContent).toContain(expected as string);
+	});
+
+	it('renders no date chip when timelineDateLabel returns null (REQ-013)', () => {
+		const entry = makeEntry({ precision: 'UNKNOWN', eventDate: undefined });
+		render(LetterCard, { entry });
+		const chip = document.querySelector('[data-testid="letter-date"]');
+		expect(chip).toBeNull();
+	});
+
+	it('shows "Unbekannt" for an empty sender, never a bare arrow (REQ-014)', () => {
+		render(LetterCard, { entry: makeEntry({ senderName: '', receiverName: 'Elfriede' }) });
+		expect(document.body.textContent).toContain('Unbekannt');
+	});
+
+	it('shows "Unbekannt" for an empty receiver (REQ-014)', () => {
+		render(LetterCard, { entry: makeEntry({ senderName: 'Karl', receiverName: '' }) });
+		expect(document.body.textContent).toContain('Unbekannt');
+	});
+
+	it('links to exactly /documents/{documentId} with no target (REQ-023)', () => {
+		render(LetterCard, { entry: makeEntry({ documentId: DOC_ID }) });
+		const link = document.querySelector('a') as HTMLAnchorElement;
+		expect(link.getAttribute('href')).toBe(`/documents/${DOC_ID}`);
+		expect(link.hasAttribute('target')).toBe(false);
+	});
+
+	it('has a touch target of at least 44px (REQ-020)', () => {
+		render(LetterCard, { entry: makeEntry() });
+		const link = document.querySelector('a') as HTMLAnchorElement;
+		expect(link.getBoundingClientRect().height).toBeGreaterThanOrEqual(44);
+	});
+});

frontend/src/lib/timeline/TimelineView.svelte

@@ -0,0 +1,107 @@
+<script lang="ts">
+import * as m from '$lib/paraglide/messages.js';
+import YearBand from './YearBand.svelte';
+import GapSpan from './GapSpan.svelte';
+import LetterCard from './LetterCard.svelte';
+import EventPill from './EventPill.svelte';
+import WorldBand from './WorldBand.svelte';
+import { entryKey } from './entryKey';
+import type { components } from '$lib/generated/api';
+
+type TimelineDTO = components['schemas']['TimelineDTO'];
+type TimelineYearDTO = components['schemas']['TimelineYearDTO'];
+
+/**
+ * Orchestrates the global timeline (REQ-001/003). Renders the year bands the DTO
+ * delivers in order — never re-sorting — interleaving a folded GapSpan for each
+ * interior run of empty years (REQ-015), then the undated bucket (REQ-016). An
+ * empty timeline shows a calm message (REQ-017). `personId` is a declared seam
+ * for the per-person rail (issue #10) and is undefined here; it is not passed to
+ * leaf cards (REQ-025). Owns no <main> — the layout does.
+ */
+let { timeline, personId = undefined }: { timeline: TimelineDTO; personId?: string } = $props();
+
+type Row = { t: 'band'; year: TimelineYearDTO } | { t: 'gap'; from: number; to: number };
+
+const rows = $derived.by<Row[]>(() => {
+	const out: Row[] = [];
+	const years = timeline.years;
+	for (let i = 0; i < years.length; i++) {
+		if (i > 0) {
+			const prev = years[i - 1].year;
+			const cur = years[i].year;
+			if (cur - prev > 1) out.push({ t: 'gap', from: prev + 1, to: cur - 1 });
+		}
+		out.push({ t: 'band', year: years[i] });
+	}
+	return out;
+});
+
+const isEmpty = $derived(timeline.years.length === 0 && timeline.undated.length === 0);
+</script>
+
+{#if isEmpty}
+	<p class="py-12 text-center font-serif text-base text-ink-2">{m.timeline_empty_state()}</p>
+{:else}
+	<!-- personId is a declared seam for the per-person Lebensweg rail (issue #10);
+	     undefined in the global view, surfaced only on the root, never passed to
+	     leaf cards (REQ-025). -->
+	<ol class="timeline-axis relative mx-auto max-w-3xl" data-person-id={personId}>
+		{#each rows as row (row.t === 'band' ? `band-${row.year.year}` : `gap-${row.from}`)}
+			<li>
+				{#if row.t === 'band'}
+					<YearBand year={row.year} />
+				{:else}
+					<GapSpan from={row.from} to={row.to} />
+				{/if}
+			</li>
+		{/each}
+	</ol>
+
+	{#if timeline.undated.length > 0}
+		<section data-testid="undated-section" class="mx-auto mt-8 max-w-3xl">
+			<h2 class="mb-3 font-serif text-sm font-bold text-ink-2">{m.timeline_undated_section()}</h2>
+			<ul class="space-y-2">
+				<!-- The undated bucket is filtered from ALL entries, so it can hold
+				     events as well as letters. Dispatch on kind/type exactly like
+				     YearBand — an event rendered as a LetterCard would link to
+				     /documents/undefined and read "Unknown → Unknown" (REQ-007/008/009). -->
+				{#each timeline.undated as entry (entryKey(entry))}
+					<li>
+						{#if entry.kind === 'EVENT'}
+							{#if entry.type === 'HISTORICAL'}
+								<WorldBand entry={entry} />
+							{:else}
+								<EventPill entry={entry} />
+							{/if}
+						{:else}
+							<LetterCard entry={entry} />
+						{/if}
+					</li>
+				{/each}
+			</ul>
+		</section>
+	{/if}
+{/if}
+
+<style>
+/* Phone (< 1024px): a single left-anchored spine. Desktop (≥ 1024px): a
+	   centered spine the bands' alternating cards sit on either side of. The
+	   spine is decorative — the chronology lives in the <ol> DOM order. */
+.timeline-axis::before {
+	content: '';
+	position: absolute;
+	top: 0;
+	bottom: 0;
+	left: 0.5rem;
+	width: 2px;
+	background: linear-gradient(var(--palette-mint), var(--palette-navy));
+}
+
+@media (min-width: 1024px) {
+	.timeline-axis::before {
+		left: 50%;
+		transform: translateX(-50%);
+	}
+}
+</style>

frontend/src/lib/timeline/TimelineView.svelte.spec.ts

@@ -0,0 +1,237 @@
+import { describe, it, expect, afterEach } from 'vitest';
+import { cleanup, render } from 'vitest-browser-svelte';
+import TimelineView from './TimelineView.svelte';
+import { makeEntry, makeYear, makeTimelineDTO } from './test-factories';
+
+afterEach(() => cleanup());
+
+describe('TimelineView', () => {
+	it('shows the empty state and no ol when there are no years and no undated (REQ-017)', () => {
+		render(TimelineView, { timeline: makeTimelineDTO() });
+		expect(document.body.textContent).toContain('Noch keine Ereignisse.');
+		expect(document.querySelector('ol')).toBeNull();
+		expect(document.querySelector('section')).toBeNull();
+	});
+
+	it('renders the timeline as a single <ol> with each band a <section>, ascending (REQ-006)', () => {
+		render(TimelineView, {
+			timeline: makeTimelineDTO({
+				years: [
+					makeYear(1914, [makeEntry({ documentId: 'a' })]),
+					makeYear(1916, [makeEntry({ documentId: 'b' })])
+				]
+			})
+		});
+		expect(document.querySelectorAll('ol')).toHaveLength(1);
+		const headings = Array.from(document.querySelectorAll('section h2')).map((h) => h.textContent);
+		expect(headings.some((t) => t?.includes('1914'))).toBe(true);
+		const order = headings.map((t) => t?.trim());
+		expect(order.indexOf('1914')).toBeLessThan(order.indexOf('1916'));
+	});
+
+	it('folds an interior run of empty years into one GapSpan (REQ-015)', () => {
+		render(TimelineView, {
+			timeline: makeTimelineDTO({
+				years: [
+					makeYear(1909, [makeEntry({ documentId: 'a' })]),
+					makeYear(1915, [makeEntry({ documentId: 'b' })])
+				]
+			})
+		});
+		expect(document.body.textContent).toContain('1910–1914');
+		expect(document.body.textContent).toContain('keine Einträge');
+	});
+
+	it('folds a single empty interior year as a single year (REQ-015)', () => {
+		render(TimelineView, {
+			timeline: makeTimelineDTO({
+				years: [
+					makeYear(1911, [makeEntry({ documentId: 'a' })]),
+					makeYear(1913, [makeEntry({ documentId: 'b' })])
+				]
+			})
+		});
+		expect(document.body.textContent).toContain('1912');
+		expect(document.body.textContent).not.toContain('1912–1912');
+	});
+
+	it('renders an "Ohne Datum" section when undated is non-empty (REQ-016)', () => {
+		render(TimelineView, {
+			timeline: makeTimelineDTO({
+				years: [makeYear(1914, [makeEntry({ documentId: 'a' })])],
+				undated: [makeEntry({ precision: 'UNKNOWN', eventDate: undefined, documentId: 'u1' })]
+			})
+		});
+		expect(document.querySelector('[data-testid="undated-section"]')).not.toBeNull();
+		expect(document.body.textContent).toContain('Ohne Datum');
+	});
+
+	it('omits the "Ohne Datum" section from the DOM when undated is empty (REQ-016)', () => {
+		render(TimelineView, {
+			timeline: makeTimelineDTO({ years: [makeYear(1914, [makeEntry({ documentId: 'a' })])] })
+		});
+		expect(document.querySelector('[data-testid="undated-section"]')).toBeNull();
+	});
+
+	it('renders all years and undated entries with personId undefined, no filtering (REQ-025)', () => {
+		render(TimelineView, {
+			timeline: makeTimelineDTO({
+				years: [
+					makeYear(1914, [makeEntry({ documentId: 'a' })]),
+					makeYear(1915, [makeEntry({ documentId: 'b' })])
+				],
+				undated: [makeEntry({ precision: 'UNKNOWN', eventDate: undefined, documentId: 'u1' })]
+			}),
+			personId: undefined
+		});
+		// Two year bands inside the <ol>, plus the separate undated section.
+		expect(document.querySelectorAll('ol section h2')).toHaveLength(2);
+		expect(document.querySelector('[data-testid="undated-section"]')).not.toBeNull();
+	});
+
+	it('renders an undated curated EVENT as a pill, not a broken letter card (REQ-008/016)', () => {
+		render(TimelineView, {
+			timeline: makeTimelineDTO({
+				undated: [
+					makeEntry({
+						kind: 'EVENT',
+						type: 'PERSONAL',
+						derived: false,
+						eventId: 'e1',
+						precision: 'UNKNOWN',
+						eventDate: undefined,
+						title: 'Auswanderung',
+						senderName: '',
+						receiverName: '',
+						documentId: undefined
+					})
+				]
+			})
+		});
+		// The event renders inside the undated section…
+		expect(document.querySelector('[data-testid="undated-section"]')).not.toBeNull();
+		expect(document.body.textContent).toContain('Auswanderung');
+		// …as an EventPill (its edit affordance), never as a letter card linking
+		// to /documents/undefined with "Unbekannt → Unbekannt".
+		expect(document.querySelector('[data-testid="event-edit"]')).not.toBeNull();
+		expect(document.querySelector('a[href="/documents/undefined"]')).toBeNull();
+		expect(document.body.textContent).not.toContain('Unbekannt');
+	});
+
+	it('renders an undated HISTORICAL EVENT as a world band, not a letter card (REQ-009/016)', () => {
+		render(TimelineView, {
+			timeline: makeTimelineDTO({
+				undated: [
+					makeEntry({
+						kind: 'EVENT',
+						type: 'HISTORICAL',
+						derived: false,
+						precision: 'UNKNOWN',
+						eventDate: undefined,
+						title: 'Weltwirtschaftskrise',
+						senderName: '',
+						receiverName: '',
+						documentId: undefined
+					})
+				]
+			})
+		});
+		expect(document.querySelector('[data-testid="undated-section"]')).not.toBeNull();
+		expect(document.body.textContent).toContain('Weltwirtschaftskrise');
+		// HISTORICAL → WorldBand carries the sr-only "Weltgeschehen" cue (REQ-018),
+		// not a broken document link.
+		expect(document.body.textContent).toContain('Weltgeschehen');
+		expect(document.querySelector('a[href="/documents/undefined"]')).toBeNull();
+	});
+
+	it('still renders an undated LETTER as a letter card (REQ-016)', () => {
+		render(TimelineView, {
+			timeline: makeTimelineDTO({
+				undated: [makeEntry({ precision: 'UNKNOWN', eventDate: undefined, documentId: 'u1' })]
+			})
+		});
+		expect(document.querySelector('a[href="/documents/u1"]')).not.toBeNull();
+	});
+
+	it('renders two derived events in one band without key collision (no-double-null-key)', () => {
+		const a = makeEntry({
+			kind: 'EVENT',
+			derived: true,
+			derivedType: 'BIRTH',
+			title: 'Geburt: Anna',
+			senderName: '',
+			receiverName: '',
+			documentId: undefined,
+			eventId: undefined,
+			linkedPersonIds: ['p1']
+		});
+		const b = makeEntry({
+			kind: 'EVENT',
+			derived: true,
+			derivedType: 'BIRTH',
+			title: 'Geburt: Bertha',
+			senderName: '',
+			receiverName: '',
+			documentId: undefined,
+			eventId: undefined,
+			linkedPersonIds: ['p2']
+		});
+		render(TimelineView, { timeline: makeTimelineDTO({ years: [makeYear(1915, [a, b])] }) });
+		expect(document.body.textContent).toContain('Geburt: Anna');
+		expect(document.body.textContent).toContain('Geburt: Bertha');
+	});
+
+	it('shows the redundant non-color cue label for each layer (REQ-018)', () => {
+		render(TimelineView, {
+			timeline: makeTimelineDTO({
+				years: [
+					makeYear(1914, [
+						makeEntry({
+							kind: 'EVENT',
+							derived: true,
+							derivedType: 'BIRTH',
+							title: 'Geburt: Hans',
+							senderName: '',
+							receiverName: '',
+							documentId: undefined
+						}),
+						makeEntry({
+							kind: 'EVENT',
+							derived: false,
+							type: 'PERSONAL',
+							eventId: 'e1',
+							title: 'Auswanderung',
+							senderName: '',
+							receiverName: '',
+							documentId: undefined
+						}),
+						makeEntry({
+							kind: 'EVENT',
+							derived: false,
+							type: 'HISTORICAL',
+							precision: 'RANGE',
+							eventDate: '1914-01-01',
+							eventDateEnd: '1918-12-31',
+							title: 'Erster Weltkrieg',
+							senderName: '',
+							receiverName: '',
+							documentId: undefined
+						})
+					])
+				]
+			})
+		});
+		expect(document.body.textContent).toContain('Weltgeschehen');
+		expect(document.body.textContent).toContain('Familie');
+		expect(document.body.textContent).toContain('Geburt');
+	});
+
+	it('places consecutive letter cards on alternating sides (REQ-004 surrogate)', () => {
+		const letters = Array.from({ length: 4 }, (_, i) => makeEntry({ documentId: `d${i}` }));
+		render(TimelineView, { timeline: makeTimelineDTO({ years: [makeYear(1909, letters)] }) });
+		const sides = Array.from(document.querySelectorAll('.letter-row')).map((el) =>
+			el.getAttribute('data-side')
+		);
+		expect(sides).toEqual(['left', 'right', 'left', 'right']);
+	});
+});