fix: normalize faster-whisper segments to dicts + in-proc auto-worker

Colab run 3 (A100) surfaced three GPU/API-path bugs mocks couldn't catch:

1. faster-whisper yields namedtuple Segments, but batch/bench consume
   them as dicts (.get) -> AttributeError 'Segment' has no attribute
   'get' on every real transcription. Engine now normalizes segments
   to dicts (_to_dict_segments) at the boundary.

2. API TranscribeOptions carries engine-irrelevant keys (formats,
   timestamps, glossary_id, post_correction, diarize); worker's
   TranscriptionOptions(**job.options) crashed with TypeError. Worker
   now filters job.options to TranscriptionOptions.__slots__.

3. in-proc server never consumed its own queue (jobs stayed queued
   forever). Added opt-in Settings.auto_worker (default off): lifespan
   starts a daemon Worker thread for inproc backend, stopped on
   shutdown. Notebook enables it via LUKESCRIBE_AUTO_WORKER=true so the
   API upload -> completed flow works end to end.

Notebook: bench manifest now uses clips schema (audio_path/duration_sec/
entities); cell 22 reads error_message/error_code; upload poll window
raised to 4min (first-run model download).

+ 5 tests (namedtuple/dict segments, API-style options, auto_worker
on/off); 136 tests pass, ruff clean.

tests/integration/test_worker.py

@@ -30,6 +30,42 @@ def _job(**kw) -> Job:
 
 
 class TestWorkerLifecycle:
+    def test_api_style_options_filtered(self, settings, tmp_path):
+        """API TranscribeOptions(엔진 무관 키 포함) → 워커가 엔진 필드만 골라 처리.
+
+        Colab 실전에서 잡이 계속 실패한 원인: job.options에 formats/timestamps/
+        diarize 등이 포함돼 TranscriptionOptions(**job.options)가 TypeError를 냄.
+        """
+        broker = InProcBroker(settings)
+        store = ResultStore(str(tmp_path / "results"))
+        worker = Worker(
+            settings=settings,
+            broker=broker,
+            store=store,
+            owner=FakeEngineOwner(),
+            ingestor=FakeIngestor(),
+        )
+        job = _job(
+            options={
+                "language": "ko",
+                "device": "auto",
+                "timestamps": True,
+                "formats": ["json", "srt"],
+                "word_timestamps": False,
+                "vad": True,
+                "hotwords": [],
+                "glossary_id": None,
+                "post_correction": None,
+                "diarize": False,
+            }
+        )
+        broker.enqueue(job)
+        worker.drain()
+        assert broker.get(job.id).status == JobStatus.COMPLETED
+        result = store.read_result(job.id)
+        assert result is not None
+        assert result.status == "completed"
+
     def test_complete_flow(self, settings, tmp_path):
         """enqueue → worker 처리 → completed + 결과 저장 + 콜백."""
         broker = InProcBroker(settings)