docs(person): ADR-039, DB diagrams, and V76 deploy runbook note

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/DEPLOYMENT.md

@@ -518,6 +518,26 @@ docker exec -i archive-db psql -U ${POSTGRES_USER} ${POSTGRES_DB} < backup-YYYYM
 
 Automated backup (nightly `pg_dump` + MinIO `mc mirror` over Tailscale to `heim-nas`) is a follow-up issue. Until that ships: **manual backups are the only recovery option.**
 
+### Deploy note — V76 (persons birth/death → date + precision, #773)
+
+V76 drops `persons.birth_year`/`death_year` after backfilling the new
+`birth_date`/`death_date` + precision columns — a **one-way migration** (Flyway cannot
+roll it back). Before deploying:
+
+1. Take a manual `pg_dump` (see above) — there is no automated nightly backup yet, so
+   confirm the dump completed before starting the deploy.
+2. No maintenance window is required: the pre-check + DDL run in one atomic Flyway
+   transaction, and this single-writer archive has no concurrent importers during deploy.
+
+If post-deploy data issues are found, restore **only the persons table** from the
+pre-migration dump (targeted restore, not a full-database restore):
+
+```bash
+pg_restore -t persons -d ${POSTGRES_DB} backup-YYYYMMDD.dump
+```
+
+(For a plain-SQL dump, extract the persons COPY block instead of replaying the full file.)
+
 ### Rollback
 
 Each release tag corresponds to a docker image tag on the host daemon (built via DooD; no registry). Rolling back to a previous tag is one command:

docs/adr/039-person-life-dates-localdate-precision.md

@@ -0,0 +1,91 @@
+# ADR-039 — Person life dates become LocalDate + DatePrecision
+
+**Status:** Accepted
+**Date:** 2026-06-12
+**Issue:** #773 (Zeitstrahl milestone, foundational)
+
+## Context
+
+`Person` stored `birthYear`/`deathYear` as `Integer`. A known exact birthday
+(`1901-03-14`) had nowhere to live, and every display was stuck at year precision.
+The Zeitstrahl's derived life-events need real dates with precision metadata, and the
+document domain already solved exactly this problem with
+`Document.documentDate` + `metaDatePrecision`.
+
+V76 replaces the two integer columns with `birth_date`/`death_date` (`DATE`, nullable)
+plus `birth_date_precision`/`death_date_precision` (`VARCHAR(16) NOT NULL DEFAULT
+'UNKNOWN'`), backfilling existing years as `YYYY-01-01` at `YEAR` precision.
+
+## Decisions
+
+### 1. `DatePrecision` stays in `document/` and is imported cross-domain
+
+The `person` package imports `org.raddatz.familienarchiv.document.DatePrecision`
+directly. The layering rule (controllers → services → own repository) governs
+service-to-repository coupling, **not** value-type sharing — an enum has no behaviour
+and no persistence side effects. Creating a `common/` package for one enum would be
+premature structure; if a third domain needs it, revisit then. The enum remains a
+verbatim mirror of the import normalizer's `Precision` values (ADR-025) — changes must
+stay in sync with `tools/import-normalizer/dates.py`.
+
+### 2. Precision columns are NOT NULL with default `UNKNOWN`
+
+Mirrors `Document.metaDatePrecision`. The illegal state "date present, precision null"
+cannot exist: the named CHECK constraints
+(`chk_person_birth_date_precision_coherence`, `…_values`,
+`chk_person_birth_before_death`, and the death-side twins) enforce
+`(date IS NULL) = (precision = 'UNKNOWN')` and the temporal order at the DB level;
+`PersonService.validateLifeDates` enforces the same rules first so users get a
+structured 400 (`INVALID_DATE_PRECISION` / `BIRTH_AFTER_DEATH`) instead of a
+constraint-violation 500.
+
+Storage accepts all seven `DatePrecision` values (enum-to-string mapping consistency),
+but the person new/edit form offers only **DAY / MONTH / YEAR** — `RANGE` and `SEASON`
+are semantically nonsensical for a birth or death, and `APPROX` is excluded from the
+form to reduce cognitive load for the senior author audience. Legacy `APPROX` rows
+still render correctly (display delegates to `formatDocumentDate`).
+
+### 3. Derived-year pattern for backward-compatible DTOs
+
+`PersonNodeDTO` (Stammbaum) and `RelationshipDTO` keep `Integer birthYear/deathYear`,
+derived null-safely in the relationship services (`birthDate != null ?
+birthDate.getYear() : null` — never 0, never empty string; REQ-PERSON-DATE-01). The
+native queries behind `PersonSummaryDTO` project
+`CAST(EXTRACT(YEAR FROM p.birth_date) AS int) AS birthYear`.
+
+### 4. `PersonSummaryDTO` intentionally exposes years only
+
+The person list/search views show year precision only; full precision lives on the
+person detail page. Do **not** add `LocalDate getBirthDate()` to the interface without
+updating all four native queries (`findAllWithDocumentCount`,
+`searchWithDocumentCount`, `findTopByDocumentCount`, `findByFilter`) — the interface
+projection is satisfied purely by the SQL SELECT aliases.
+
+### 5. `preferHumanDate` extends ADR-025's human-edit-preserve rule
+
+The importer stays year-shaped: `PersonUpsertCommand` keeps `Integer birthYear/
+deathYear` because the spreadsheet only knows a year — pushing `LocalDate` into the
+importer would fabricate precision. On upsert, `PersonService.preferHumanDate` returns
+a `DatePrecisionPair` record (date and precision travel as one value so they cannot go
+out of sync):
+
+- existing precision DAY/MONTH/SEASON/RANGE/APPROX → hand-entered, preserved verbatim;
+- existing precision YEAR/UNKNOWN → refreshed from the canonical year as
+  `YYYY-01-01` + `YEAR` (or cleared to null/`UNKNOWN` when the sheet has no year).
+
+The original integer/string `preferHuman` overloads remain for non-date fields.
+
+### 6. Known limitation — mixed-precision comparison
+
+`validateLifeDates` compares stored `LocalDate` values. A DAY-precision birth late in
+the same year as a YEAR-precision death (stored as Jan 1st) is rejected with
+`BIRTH_AFTER_DEATH`. This is intentional; the `error_birth_after_death` i18n message
+carries the workaround hint (enter the following year as the death year).
+
+## Consequences
+
+- V76 is one-way (columns dropped). Rollback = targeted `pg_restore -t persons` from
+  the pre-deploy dump — see `docs/DEPLOYMENT.md` §5.
+- Exact dates now render on person cards, hover cards, and the mention dropdown; the
+  Stammbaum and person list are visually unchanged.
+- The Zeitstrahl can derive birth/death life-events at full precision.

docs/architecture/db/db-orm.puml

@@ -1,6 +1,6 @@
 @startuml db-orm
-' Schema source: Flyway V1–V72 (excl. V37, V43 — intentionally removed)
-' Schema as of:  V72 (2026-06-08)
+' Schema source: Flyway V1–V76 (excl. V37, V43 — intentionally removed)
+' Schema as of:  V76 (2026-06-12)
 ' ⚠ This is a versioned snapshot. Update when the schema changes significantly.
 
 hide circle
@@ -184,8 +184,10 @@ package "Persons" {
     title : VARCHAR(50)
     person_type : VARCHAR(20) NOT NULL
     notes : TEXT
-    birth_year : INTEGER
-    death_year : INTEGER
+    birth_date : DATE
+    birth_date_precision : VARCHAR(16) NOT NULL
+    death_date : DATE
+    death_date_precision : VARCHAR(16) NOT NULL
     generation : SMALLINT
     family_member : BOOLEAN NOT NULL
     source_ref : VARCHAR(255) UNIQUE

docs/architecture/db/db-relationships.puml

@@ -4,6 +4,8 @@
 ' ⚠ This is a versioned snapshot. Update when the schema changes significantly.
 ' Note: V69 adds columns only (persons.source_ref, tag.source_ref, document
 ' precision/attribution fields); no new FK relationships, so this diagram is unchanged.
+' Note: V76 swaps persons.birth_year/death_year for birth_date/death_date +
+' precision columns; columns only, no new FK relationships, diagram unchanged.
 
 hide circle
 skinparam linetype ortho