Merge feat/297-cheaper-ai into feat/299-correlation-simplify

Resolve upload.py (no-scene fallback uses the new _correlate with #298's
non_event_chatter reason) and chatter_classifier docstring (gate built, off by
default). Fold intelligence._llm_bool into incident_correlator.parse_llm_bool (#88).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

drb-c2-core/tests/test_ai_flag_gating.py

@@ -219,15 +219,21 @@ async def test_transcript_correction_is_skipped_when_its_flag_is_off():
          patch.object(transcription, "fstore") as fs, \
          patch.object(transcription, "ai_health") as health, \
          patch.object(transcription, "transcript_correction") as tc, \
-         patch("asyncio.to_thread", AsyncMock(return_value=("units respond", [], False))):
+         patch.object(transcription.settings, "openai_api_key", "k"), \
+         patch.object(transcription.settings, "groq_api_key", None), \
+         patch.object(transcription, "_download", lambda uri: "/nonexistent.mp3"), \
+         patch.object(transcription, "_sync_transcribe_file", lambda *a, **k: {
+             "text": "units respond to the fire on Main Street", "segments": [],
+             "degenerate": False, "duration": 3.0, "confidence": None}):
         fs.doc_set = AsyncMock()
         health.report_healthy = AsyncMock()
         health.report_failure = AsyncMock()
         tc.correct = AsyncMock()
-        await transcription.transcribe_call(
+        text, _ = await transcription.transcribe_call(
             "call-1", "gs://bucket/call-1.mp3", "PD Dispatch", system_id="sys-1"
         )
 
+    assert text == "units respond to the fire on Main Street", "the transcript must still be produced"
     tc.correct.assert_not_awaited()