Add ASR interim results support in Assistant model and API

- Introduced `asr_interim_enabled` field in the Assistant model to control interim ASR results.
- Updated AssistantBase and AssistantUpdate schemas to include the new field.
- Modified the database schema to add the `asr_interim_enabled` column.
- Enhanced runtime metadata to reflect interim ASR settings.
- Updated API endpoints and tests to validate the new functionality.
- Adjusted documentation to include details about interim ASR results configuration.

engine/tests/test_duplex_asr_modes.py

@@ -145,10 +145,11 @@ async def test_start_asr_capture_uses_streaming_begin(monkeypatch):
 
 
 @pytest.mark.asyncio
-async def test_start_asr_capture_uses_offline_interim_control(monkeypatch):
+async def test_start_asr_capture_uses_offline_interim_control_when_enabled(monkeypatch):
     asr = _FakeOfflineASR()
     pipeline = _build_pipeline(monkeypatch, asr)
     pipeline._asr_mode = "offline"
+    pipeline._runtime_asr["enableInterim"] = True
     pipeline._pending_speech_audio = b"\x00" * 320
     pipeline._pre_speech_buffer = b"\x00" * 640
 
@@ -159,6 +160,69 @@ async def test_start_asr_capture_uses_offline_interim_control(monkeypatch):
     assert pipeline._asr_capture_active is True
 
 
+@pytest.mark.asyncio
+async def test_start_asr_capture_skips_offline_interim_control_when_disabled(monkeypatch):
+    asr = _FakeOfflineASR()
+    pipeline = _build_pipeline(monkeypatch, asr)
+    pipeline._asr_mode = "offline"
+    pipeline._runtime_asr["enableInterim"] = False
+    pipeline._pending_speech_audio = b"\x00" * 320
+    pipeline._pre_speech_buffer = b"\x00" * 640
+
+    await pipeline._start_asr_capture()
+
+    assert asr.start_interim_calls == 0
+    assert asr.sent_audio
+    assert pipeline._asr_capture_active is True
+
+
+@pytest.mark.asyncio
+async def test_offline_interim_callback_ignored_when_disabled(monkeypatch):
+    asr = _FakeOfflineASR()
+    pipeline = _build_pipeline(monkeypatch, asr)
+    pipeline._asr_mode = "offline"
+    pipeline._runtime_asr["enableInterim"] = False
+
+    captured_events = []
+    captured_deltas = []
+
+    async def _capture_event(event: Dict[str, Any], priority: int = 20):
+        _ = priority
+        captured_events.append(event)
+
+    async def _capture_delta(text: str):
+        captured_deltas.append(text)
+
+    monkeypatch.setattr(pipeline, "_send_event", _capture_event)
+    monkeypatch.setattr(pipeline, "_emit_transcript_delta", _capture_delta)
+
+    await pipeline._on_transcript_callback("ignored interim", is_final=False)
+
+    assert captured_events == []
+    assert captured_deltas == []
+    assert pipeline._latest_asr_interim_text == ""
+
+
+@pytest.mark.asyncio
+async def test_offline_final_callback_emits_when_interim_disabled(monkeypatch):
+    asr = _FakeOfflineASR()
+    pipeline = _build_pipeline(monkeypatch, asr)
+    pipeline._asr_mode = "offline"
+    pipeline._runtime_asr["enableInterim"] = False
+
+    captured_events = []
+
+    async def _capture_event(event: Dict[str, Any], priority: int = 20):
+        _ = priority
+        captured_events.append(event)
+
+    monkeypatch.setattr(pipeline, "_send_event", _capture_event)
+
+    await pipeline._on_transcript_callback("final only", is_final=True)
+
+    assert any(event.get("type") == "transcript.final" for event in captured_events)
+
+
 @pytest.mark.asyncio
 async def test_streaming_eou_falls_back_to_latest_interim(monkeypatch):
     asr = _FakeStreamingASR()