feat(recall): telemetryEvents — recall_shown/opened/dismissed/snoozed zod schemas (#6 v0.2.3)

- RecallShownPayload { noteId, ageDays: int>=0 } .strict()
- recall_opened/dismissed/snoozed → NoteIdPayload 재사용
- TelemetryEventSchema union 15 → 19
- 단위 +3 cases (recall_shown valid, extra field 거부, opened/dismissed/snoozed valid)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/unit/telemetryEvents.test.ts

@@ -306,3 +306,30 @@ describe('validateEvent — tag vocab', () => {
     })).toThrow();
   });
 });
+
+describe('validateEvent — recall', () => {
+  it('accepts recall_shown event', () => {
+    const e = validateEvent({
+      ts: '2026-05-02T00:00:00.000Z',
+      kind: 'recall_shown',
+      payload: { noteId: 'n1', ageDays: 14 }
+    });
+    expect(e.kind).toBe('recall_shown');
+  });
+
+  it('rejects recall_shown with extra field (privacy)', () => {
+    expect(() => validateEvent({
+      ts: '2026-05-02T00:00:00.000Z',
+      kind: 'recall_shown',
+      payload: { noteId: 'n1', ageDays: 14, content: 'leak' }
+    })).toThrow();
+  });
+
+  it('accepts recall_opened/dismissed/snoozed (NoteIdPayload reused)', () => {
+    for (const kind of ['recall_opened', 'recall_dismissed', 'recall_snoozed'] as const) {
+      const e = validateEvent({ ts: '2026-05-02T00:00:00.000Z', kind, payload: { noteId: 'n1' } });
+      expect(e.kind).toBe(kind);
+    }
+  });
+});
+