feat(relationship): date+precision edit UI, notes, and read-view display

Regenerate api.ts for the LocalDate+DatePrecision RelationshipDTO /
RelationshipUpsertRequest and the new PUT, then migrate every caller:

- RelationshipDateField (mirrors PersonLifeDateField: DAY/MONTH/YEAR, 44px
  targets, labelled, semantic dark-mode tokens, relation_* i18n keys).
- AddRelationshipForm is now upsert-capable: an optional `relationship` prop
  pre-fills type, person, both dates+precision and notes; posts to
  ?/updateRelationship (else ?/addRelationship); the submit control disables and
  shows a progress spinner while a request is in flight (REQ-019); notes textarea
  (<=2000).
- RelationshipChip gains an accessible Edit affordance (canWrite + onEdit);
  StammbaumCard wires it, formats the date range via formatRelationshipDateRange,
  and sorts by fromDate. PersonRelationshipsCard (read view) shows the date range
  and notes; no dates -> no date line.
- persons/[id]/edit/+page.server.ts: updateRelationship action (PUT) + the
  addRelationship action reshaped to date+precision+notes (empty date omits
  precision for coherence).
- Genealogy callers fixed for the dropped year fields: familyForest spouse-order
  and StammbaumConnectors ended-edge dashing now key off fromDate/toDate.
- i18n relation_* form keys in de/en/es.

REQ-004, REQ-014, REQ-015, REQ-016, REQ-019

Refs #837
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/routes/persons/[id]/edit/page.server.spec.ts

@@ -97,3 +97,98 @@ describe('persons/[id]/edit update action — generation (#689)', () => {
 		expect(body).toHaveProperty('generation', 3);
 	});
 });
+
+describe('persons/[id]/edit relationship actions (#837)', () => {
+	function relForm(overrides: Record<string, string | null> = {}): Request {
+		const fd = new FormData();
+		fd.set('relatedPersonId', 'p2');
+		fd.set('relationType', 'SPOUSE_OF');
+		for (const [k, v] of Object.entries(overrides)) {
+			if (v == null) fd.delete(k);
+			else fd.set(k, v);
+		}
+		return new Request('http://localhost/persons/p1/edit', { method: 'POST', body: fd });
+	}
+
+	it('addRelationship posts date + precision + notes', async () => {
+		const post = vi.fn().mockResolvedValue({ response: { ok: true, status: 200 }, data: {} });
+		vi.mocked(createApiClient).mockReturnValue({ POST: post } as unknown as ReturnType<
+			typeof createApiClient
+		>);
+		const request = relForm({
+			fromDate: '1923-05-12',
+			fromDatePrecision: 'DAY',
+			notes: 'Hochzeit'
+		});
+
+		// eslint-disable-next-line @typescript-eslint/no-explicit-any
+		await actions.addRelationship({ request, params: { id: 'p1' }, fetch: mockFetch } as any);
+
+		const [path, opts] = post.mock.calls[0];
+		expect(path).toBe('/api/persons/{id}/relationships');
+		expect(opts.body).toMatchObject({
+			relatedPersonId: 'p2',
+			relationType: 'SPOUSE_OF',
+			fromDate: '1923-05-12',
+			fromDatePrecision: 'DAY',
+			notes: 'Hochzeit'
+		});
+	});
+
+	it('addRelationship omits precision when the date is empty (coherence)', async () => {
+		const post = vi.fn().mockResolvedValue({ response: { ok: true, status: 200 }, data: {} });
+		vi.mocked(createApiClient).mockReturnValue({ POST: post } as unknown as ReturnType<
+			typeof createApiClient
+		>);
+		const request = relForm({ fromDatePrecision: 'DAY' }); // precision but no date
+
+		// eslint-disable-next-line @typescript-eslint/no-explicit-any
+		await actions.addRelationship({ request, params: { id: 'p1' }, fetch: mockFetch } as any);
+
+		const body = post.mock.calls[0][1].body;
+		expect(body).not.toHaveProperty('fromDate');
+		expect(body).not.toHaveProperty('fromDatePrecision');
+	});
+
+	it('updateRelationship PUTs to the relId path with the new body', async () => {
+		const put = vi.fn().mockResolvedValue({ response: { ok: true, status: 200 }, data: {} });
+		vi.mocked(createApiClient).mockReturnValue({ PUT: put } as unknown as ReturnType<
+			typeof createApiClient
+		>);
+		const request = relForm({ relId: 'rel-9', fromDate: '1923-05-12', fromDatePrecision: 'DAY' });
+
+		// eslint-disable-next-line @typescript-eslint/no-explicit-any
+		await actions.updateRelationship({ request, params: { id: 'p1' }, fetch: mockFetch } as any);
+
+		const [path, opts] = put.mock.calls[0];
+		expect(path).toBe('/api/persons/{id}/relationships/{relId}');
+		expect(opts.params.path).toMatchObject({ id: 'p1', relId: 'rel-9' });
+		expect(opts.body).toMatchObject({
+			relatedPersonId: 'p2',
+			relationType: 'SPOUSE_OF',
+			fromDate: '1923-05-12',
+			fromDatePrecision: 'DAY'
+		});
+	});
+
+	it('updateRelationship surfaces a backend error as a fail', async () => {
+		const put = vi.fn().mockResolvedValue({
+			response: { ok: false, status: 400 },
+			error: { code: 'INVALID_RELATIONSHIP_DATES' }
+		});
+		vi.mocked(createApiClient).mockReturnValue({ PUT: put } as unknown as ReturnType<
+			typeof createApiClient
+		>);
+		const request = relForm({ relId: 'rel-9' });
+
+		const result = (await actions.updateRelationship({
+			request,
+			params: { id: 'p1' },
+			fetch: mockFetch
+			// eslint-disable-next-line @typescript-eslint/no-explicit-any
+		} as any)) as { status: number; data: { relationshipError: string } };
+
+		expect(result.status).toBe(400);
+		expect(result.data.relationshipError).toBeTruthy();
+	});
+});