feat(retry): telemetry ai_retry_manual + stats AI 수동 재시도 (#2 v0.2.3)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/unit/telemetryEvents.test.ts

@@ -250,3 +250,31 @@ describe('ollama_unreachable / ollama_recovered / ollama_recheck_manual events',
     })).toThrow();
   });
 });
+
+describe('ai_retry_manual event', () => {
+  it('parses valid ai_retry_manual', () => {
+    const ev = validateEvent({
+      ts: '2026-05-01T00:00:00.000Z',
+      kind: 'ai_retry_manual',
+      payload: { failedCount: 5 }
+    });
+    if (ev.kind !== 'ai_retry_manual') throw new Error('discriminant');
+    expect(ev.payload.failedCount).toBe(5);
+  });
+
+  it('rejects ai_retry_manual with failedCount=0 (≥1 invariant)', () => {
+    expect(() => validateEvent({
+      ts: '2026-05-01T00:00:00.000Z',
+      kind: 'ai_retry_manual',
+      payload: { failedCount: 0 }
+    })).toThrow();
+  });
+
+  it('rejects ai_retry_manual with extra payload field (privacy invariant)', () => {
+    expect(() => validateEvent({
+      ts: '2026-05-01T00:00:00.000Z',
+      kind: 'ai_retry_manual',
+      payload: { failedCount: 5, rawText: 'leak' }
+    })).toThrow();
+  });
+});