fix(timeline): show EventPill provenance even when the event has no date

The provenance token (abgeleitet/kuratiert) was nested inside the
{#if dateLabel} block, so an undated or UNKNOWN-precision event — e.g.
one in the undated bucket — rendered no provenance at all. Compose the
subtitle as an optional "{date} · " prefix in front of the always-present
provenance instead.

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

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

@@ -120,4 +120,23 @@ describe('EventPill', () => {
 		expect(document.body.textContent).not.toContain('persönlich');
 		expect(document.body.textContent).not.toContain('SEASON');
 	});
+
+	it('still shows the provenance token when the event has no date label (REQ-007)', () => {
+		// An undated / UNKNOWN-precision event (e.g. in the undated bucket) yields a
+		// null dateLabel; provenance must not be gated behind the date.
+		const entry = makeEntry({
+			kind: 'EVENT',
+			derived: true,
+			derivedType: 'BIRTH',
+			title: 'Geburt: Hans',
+			senderName: '',
+			receiverName: '',
+			precision: 'UNKNOWN',
+			eventDate: undefined,
+			documentId: undefined
+		});
+		expect(timelineDateLabel(entry.eventDate, entry.precision, entry.eventDateEnd)).toBeNull();
+		render(EventPill, { entry });
+		expect(document.body.textContent).toContain(m.timeline_provenance_derived());
+	});
 });