feat(relationship): editable relationships with LocalDate+DatePrecision dates and notes (#841)

Closes #837

Makes `PersonRelationship` fully editable (type, related person, dates, notes), migrates its dates from `Integer fromYear/toYear` to `LocalDate + DatePrecision` (mirroring the #773 person pattern, ADR-039 / V76), activates the previously-dead `notes` column, and gives the Zeitstrahl's derived **Heirat** events full date precision for free.

Both Open Decisions confirmed as adopted: **no `@Version`** (last-write-wins, single-writer archive) and **`DELETE` ownership-mismatch aligned 403 → 404** (anti-enumeration, matching the new `PUT`).

## What's in it
- **V78** migrates `person_relationships.from_year/to_year` → `from_date`/`to_date` + NOT-NULL `*_date_precision` (default `UNKNOWN`); pre-check abort on corrupt years, `YYYY-01-01`/`YEAR` backfill, 5 named CHECK constraints, year columns dropped.
- **`PUT /api/persons/{id}/relationships/{relId}`** (`@RequirePermission(WRITE_ALL)`) re-runs every create invariant (self / coherence / order / reverse-PARENT_OF / duplicate) and re-flags family membership; orientation preserved per viewpoint.
- New `ErrorCode.INVALID_RELATIONSHIP_DATES` registered in all four sites (§3.6).
- `TimelineEventService` sources the derived marriage date from `SPOUSE_OF.fromDate` + precision.
- Frontend: `RelationshipDateField` (DAY/MONTH/YEAR), upsert-capable `AddRelationshipForm` (pre-fill + notes + in-flight submit lock), `RelationshipChip` Edit affordance, `updateRelationship` server action, read-view date range + notes, `formatRelationshipDateRange` helper. `api.ts` regenerated.
- Docs: ADR-044, db-orm/db-relationships diagrams, DEPLOYMENT §5 deploy note, RTM REQ-001…REQ-019.

## Requirements
All 19 EARS requirements implemented red/green and marked `Done` in `.specify/rtm.md`.

## Test plan
- **Backend** (targeted, green): `RelationshipMigrationTest` (Testcontainers pg16, 8), `RelationshipServiceTest` (22), `RelationshipControllerTest` (15), `RelationshipServiceIntegrationTest` (real DB, 10), `DerivedEventsAssemblyTest` (17), `ArchitectureTest` (14); `clean package` builds.
- **Frontend** (green): `relationshipDates.spec.ts`, `AddRelationshipForm.svelte.spec.ts`, `RelationshipChip.svelte.spec.ts`, `PersonRelationshipsCard.svelte.test.ts`, `page.server.spec.ts`, `messages.spec.ts`. `npm run check` = 798 (below the ~834 baseline); `npm run lint` clean.

## Notes for reviewers
- **Spec deviation:** the edit form was built by making `AddRelationshipForm` upsert-capable rather than a duplicate `EditRelationshipForm` (DRY); RTM rows reference `AddRelationshipForm.svelte.spec.ts`.
- `api.ts` regenerated from the live spec; only relationship-relevant hunks remain (one springdoc `PageableObject` field-reorder pruned).
- **Deploy:** V78 is one-way and not rolling-deploy-safe — stop old JAR → start new JAR (Flyway runs first); targeted `pg_restore -t person_relationships` for rollback. No maintenance window.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Marcel <marcel@familienarchiv>
Reviewed-on: #841

frontend/src/lib/person/relationship/AddRelationshipForm.svelte.test.ts

@@ -33,36 +33,6 @@ describe('AddRelationshipForm', () => {
 		expect(optionValues).toContain('OTHER');
 	});
 
-	it('shows the year-error alert when toYear is before fromYear', async () => {
-		render(AddRelationshipForm, { props: { personId: 'p-1' } });
-
-		await page.getByRole('button', { name: /hinzufügen/i }).click();
-
-		const fromInput = document.querySelector('input[name="fromYear"]') as HTMLInputElement;
-		const toInput = document.querySelector('input[name="toYear"]') as HTMLInputElement;
-		fromInput.value = '1923';
-		fromInput.dispatchEvent(new Event('input', { bubbles: true }));
-		toInput.value = '1920';
-		toInput.dispatchEvent(new Event('input', { bubbles: true }));
-
-		await expect.element(page.getByText(/bis-jahr darf nicht vor von-jahr/i)).toBeVisible();
-	});
-
-	it('does not show the year-error when toYear equals fromYear', async () => {
-		render(AddRelationshipForm, { props: { personId: 'p-1' } });
-
-		await page.getByRole('button', { name: /hinzufügen/i }).click();
-
-		const fromInput = document.querySelector('input[name="fromYear"]') as HTMLInputElement;
-		const toInput = document.querySelector('input[name="toYear"]') as HTMLInputElement;
-		fromInput.value = '1923';
-		fromInput.dispatchEvent(new Event('input', { bubbles: true }));
-		toInput.value = '1923';
-		toInput.dispatchEvent(new Event('input', { bubbles: true }));
-
-		await expect.element(page.getByText(/bis-jahr darf nicht/i)).not.toBeInTheDocument();
-	});
-
 	it('cancel button closes the form', async () => {
 		render(AddRelationshipForm, { props: { personId: 'p-1' } });
 
@@ -136,25 +106,4 @@ describe('AddRelationshipForm', () => {
 			expect(submitBtn!.disabled).toBe(true);
 		});
 	});
-
-	it('keeps submit disabled when there is a yearError', async () => {
-		render(AddRelationshipForm, { props: { personId: 'p-1' } });
-
-		await page.getByRole('button', { name: /hinzufügen/i }).click();
-
-		const fromInput = document.querySelector('input[name="fromYear"]') as HTMLInputElement;
-		const toInput = document.querySelector('input[name="toYear"]') as HTMLInputElement;
-		const relInput = document.querySelector('input[name="relatedPersonId"]') as HTMLInputElement;
-		fromInput.value = '1923';
-		fromInput.dispatchEvent(new Event('input', { bubbles: true }));
-		toInput.value = '1920';
-		toInput.dispatchEvent(new Event('input', { bubbles: true }));
-		relInput.value = 'p-other';
-		relInput.dispatchEvent(new Event('input', { bubbles: true }));
-
-		await vi.waitFor(() => {
-			const submitBtn = document.querySelector('button[type="submit"]') as HTMLButtonElement;
-			expect(submitBtn.disabled).toBe(true);
-		});
-	});
 });