docs(rtm): trace #835 REQ-001..014 to their tests

Add one row per requirement for the zeitstrahl-tag-chips feature, each mapped
to its implementation file(s) and the test(s) that prove it, Status=Done.

Refs #835
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.specify/rtm.md

@@ -139,3 +139,18 @@
 | REQ-014 | no change to DTO order, density threshold (12), gap-folding, or ol/section/h2 structure | #833 | zeitstrahl-visual-fidelity | `frontend/src/lib/timeline/*` | existing timeline + `zeitstrahl/page.server.test.ts` suites stay green (142 tests) | Done |
 | REQ-015 | new user-facing strings are Paraglide keys present in de/en/es with matching key sets | #833 | zeitstrahl-visual-fidelity | `frontend/messages/{de,en,es}.json` | `messages.spec.ts#zeitstrahl visual-fidelity keys are present in all locales`, `#identical key sets` | Done |
 | REQ-016 | LetterCard with no title → no ✉, no sr-only "Brief"; sender→receiver + date still render | #833 | zeitstrahl-visual-fidelity | `frontend/src/lib/timeline/LetterCard.svelte` | `LetterCard.svelte.spec.ts#renders no ✉ glyph and no "Brief" label when the title is empty` | Done |
+| REQ-001 | TimelineEntryDTO carries rootTagId/rootTagName/rootTagColor for LETTER entries, assembled in-transaction (id+name+token only) | #835 | zeitstrahl-tag-chips | `timeline/TimelineEntryDTO`, `timeline/TimelineService#mapDocument` | `TimelineServiceTest#letter_with_tags_carries_its_primary_root_tag` | Done |
+| REQ-002 | the three root-tag fields are nullable and not `@Schema(requiredMode = REQUIRED)` | #835 | zeitstrahl-tag-chips | `timeline/TimelineEntryDTO`, `frontend/src/lib/generated/api.ts` (optional) | `TimelineServiceTest#untagged_letter_has_no_root_tag_fields` (+ regenerated `api.ts` shows `rootTag*?`) | Done |
+| REQ-003 | primary tag = root ancestor of the alphabetically-first assigned tag, resolved via TagService | #835 | zeitstrahl-tag-chips | `tag/TagService#resolveRootTags`, `timeline/TimelineService#primaryTag` | `TimelineServiceTest#letter_with_tags_carries_its_primary_root_tag`, `TagServiceTest#resolveRootTags_walksChildToRoot_withRootColor`, `TagServiceIntegrationTest#resolveRootTags_walksPersistedChainToRoot_withRootColor` | Done |
+| REQ-004 | roots resolved in a single batched/memoized pass (≤ M findAncestorIds, no per-letter N+1); color from the root token | #835 | zeitstrahl-tag-chips | `tag/TagService#resolveRootTags`, `timeline/TimelineService#resolveLetterRootTags` | `TagServiceTest#resolveRootTags_memoizesPerDistinctTag_noNPlusOne`, `TimelineServiceTest#root_tags_resolved_in_a_single_batched_pass` | Done |
+| REQ-005 | a letter with no tags → all three fields null; LetterCard renders no chip | #835 | zeitstrahl-tag-chips | `timeline/TimelineService#mapDocument`, `frontend/src/lib/timeline/LetterCard.svelte` | `TimelineServiceTest#untagged_letter_has_no_root_tag_fields`, `LetterCard.svelte.spec.ts#renders no chip when the letter has no root tag` | Done |
+| REQ-006 | a letter with multiple tags → exactly one primary root (deterministic) | #835 | zeitstrahl-tag-chips | `timeline/TimelineService#primaryTag` | `TimelineServiceTest#letter_with_tags_carries_its_primary_root_tag`, `LetterCard.svelte.spec.ts#renders one root-tag chip beneath the meta line` | Done |
+| REQ-007 | a colorless root → rootTagColor null; frontend renders a neutral chip, no `var(--c-tag-)` | #835 | zeitstrahl-tag-chips | `tag/TagService#resolveRootTags`, `frontend/src/lib/timeline/TagChip.svelte` | `TagServiceTest#resolveRootTags_returnsNullColor_whenRootHasNoColor`, `TimelineServiceTest#letter_primary_root_without_color_yields_null_color`, `TagChip.svelte.spec.ts#renders a neutral chip with no --c-tag- binding when color is null` | Done |
+| REQ-008 | LetterCard with a rootTagName renders one §3 chip beneath the meta line | #835 | zeitstrahl-tag-chips | `frontend/src/lib/timeline/TagChip.svelte`, `LetterCard.svelte` | `TagChip.svelte.spec.ts#renders the tag name`, `LetterCard.svelte.spec.ts#renders one root-tag chip beneath the meta line` | Done |
+| REQ-008a | a long name truncates with ellipsis, no horizontal overflow at 320px; full name in the chip title | #835 | zeitstrahl-tag-chips | `frontend/src/lib/timeline/TagChip.svelte`, `LetterCard.svelte` | `LetterCard.svelte.spec.ts#keeps a long tag name from overflowing the card at 320px`, `TagChip.svelte.spec.ts#exposes the full name as the chip title` | Done |
+| REQ-009 | chip color applied via `var(--c-tag-{token})`, no raw hex | #835 | zeitstrahl-tag-chips | `frontend/src/lib/timeline/TagChip.svelte` | `TagChip.svelte.spec.ts#applies the color via var(--c-tag-{token}), never raw hex` | Done |
+| REQ-010 | rootTagName rendered via `{...}` escaping; no `{@html}` in lib/timeline | #835 | zeitstrahl-tag-chips | `frontend/src/lib/timeline/TagChip.svelte` | `TagChip.svelte.spec.ts#renders an HTML-bearing name as inert text`, `grep -rn '@html' frontend/src/lib/timeline/` → zero | Done |
+| REQ-011 | colored square aria-hidden; sr-only theme label prefix so color is never the only cue | #835 | zeitstrahl-tag-chips | `frontend/src/lib/timeline/TagChip.svelte` | `TagChip.svelte.spec.ts#prefixes the name with an sr-only theme label and a decorative square` | Done |
+| REQ-012 | chip renders wherever a LetterCard renders (global timeline + expanded YearLetterStrip) | #835 | zeitstrahl-tag-chips | `frontend/src/lib/timeline/LetterCard.svelte` | `LetterCard.svelte.spec.ts#renders the chip inside an expanded YearLetterStrip too` | Done |
+| REQ-013 | sr-only theme label is a Paraglide key present in de/en/es | #835 | zeitstrahl-tag-chips | `frontend/messages/{de,en,es}.json` | `messages.spec.ts#zeitstrahl tag-chip label key is present in all locales` | Done |
+| REQ-014 | GET /api/timeline stays read-only (READ_ALL); no new endpoint/ErrorCode/IDOR; assembly logs UUIDs only | #835 | zeitstrahl-tag-chips | `timeline/TimelineController` (unchanged), `timeline/TimelineService` | `TimelineControllerTest#returns_200_with_read_all_permission`, `#returns_403_when_authenticated_without_read_all` (unchanged path); no tag names logged (review) | Done |