fix(insta-render): F6 ReliableQueue 적용 — BLMOVE + ack/fail (F6 part 2)

- worker.py: BLPOP → ReliableQueue.dequeue / ack / fail / startup recovery
- _process_one: 예외 시 webhook(failed) 후 raise — poll_once가 fail(raw, payload)
  로 retry/dead-letter 처리
- poll_once 함수 추가 (테스트 단위)
- Dockerfile: build context=services/ 로 올리고 _shared 포함, PYTHONPATH=/app
- docker-compose.yml: insta-render build context 갱신

기존 webhook 호출 동작은 그대로 (멱등) — retry 시 매번 NAS에 failed 통보되어도
마지막 상태만 보임. dead-letter는 운영 모니터링으로 별도 처리.

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

services/insta-render/tests/test_worker.py

@@ -112,11 +112,88 @@ async def test_process_one_render_failure_reports_failed(monkeypatch, fake_slate
     worker.NAS_BASE_URL = "http://nas.test"
 
     async with httpx.AsyncClient() as client:
-        await worker._process_one(client, {
-            "task_id": "t-3",
-            "params": {"slate_id": 99},
-        })
+        # F6: _process_one은 webhook(failed) 호출 후 raise — poll_once가 fail(raw)로 retry/dead-letter.
+        with pytest.raises(RuntimeError, match="Chromium"):
+            await worker._process_one(client, {
+                "task_id": "t-3",
+                "params": {"slate_id": 99},
+            })
 
     last = calls[-1]
     assert last["status"] == "failed"
     assert "Chromium" in last["error"]
+
+
+# ----- F6: ReliableQueue (ack on success, fail on exception) -----
+
+@pytest.mark.asyncio
+async def test_poll_once_acks_on_success(monkeypatch):
+    """F6 — 성공 시 queue.ack(raw) 호출 + fail 안 부름."""
+    fake_payload = {
+        "task_id": "t-ok",
+        "params": {"slate_id": 7, "theme": "default"},
+    }
+    fake_raw = json.dumps(fake_payload).encode()
+
+    fake_queue = AsyncMock()
+    fake_queue.dequeue = AsyncMock(return_value=(fake_payload, fake_raw))
+    fake_queue.ack = AsyncMock()
+    fake_queue.fail = AsyncMock()
+
+    process_mock = AsyncMock()
+    monkeypatch.setattr(worker, "_process_one", process_mock)
+
+    async with httpx.AsyncClient() as client:
+        handled = await worker.poll_once(fake_queue, client)
+
+    assert handled is True
+    process_mock.assert_awaited_once()
+    fake_queue.ack.assert_awaited_once_with(fake_raw)
+    fake_queue.fail.assert_not_awaited()
+
+
+@pytest.mark.asyncio
+async def test_poll_once_calls_fail_on_exception(monkeypatch):
+    """F6 — _process_one 예외 시 queue.fail(raw, payload) 호출."""
+    fake_payload = {
+        "task_id": "t-err",
+        "params": {"slate_id": 9, "theme": "default"},
+    }
+    fake_raw = json.dumps(fake_payload).encode()
+
+    fake_queue = AsyncMock()
+    fake_queue.dequeue = AsyncMock(return_value=(fake_payload, fake_raw))
+    fake_queue.ack = AsyncMock()
+    fake_queue.fail = AsyncMock()
+
+    async def boom(client, payload):
+        raise RuntimeError("simulated dispatch failure")
+
+    monkeypatch.setattr(worker, "_process_one", boom)
+
+    async with httpx.AsyncClient() as client:
+        handled = await worker.poll_once(fake_queue, client)
+
+    assert handled is True
+    fake_queue.fail.assert_awaited_once_with(fake_raw, fake_payload)
+    fake_queue.ack.assert_not_awaited()
+
+
+@pytest.mark.asyncio
+async def test_poll_once_returns_false_on_timeout(monkeypatch):
+    """F6 — dequeue가 None 반환(타임아웃)이면 False 리턴, ack/fail 안 부름."""
+    fake_queue = AsyncMock()
+    fake_queue.dequeue = AsyncMock(return_value=None)
+    fake_queue.ack = AsyncMock()
+    fake_queue.fail = AsyncMock()
+
+    process_mock = AsyncMock()
+    monkeypatch.setattr(worker, "_process_one", process_mock)
+
+    async with httpx.AsyncClient() as client:
+        handled = await worker.poll_once(fake_queue, client)
+
+    assert handled is False
+    process_mock.assert_not_awaited()
+    fake_queue.ack.assert_not_awaited()
+    fake_queue.fail.assert_not_awaited()