STT-Dienst: Kern, HTTP/WebSocket/Wyoming-Service, CLI, Tests, systemd-Unit

- stt_core.py: Whisper-Engine (einmal laden, CPU-Fallback), Audio-Dekodierung
  jedes Formats, Halluzinationsfilter, Äußerungserkennung per Silero-VAD
- stt_service.py: /health, /v1/audio/transcriptions (OpenAI), /transcribe (Rohdaten),
  WS /ws/stream; Inferenz im Worker-Thread, begrenzte Warteschlange (503)
- stt_wyoming.py: Home-Assistant-Anbindung (TCP 10300)
- stt_cli.py: Datei/Mikrofon über den Dienst oder lokal
- Tests (Unit + Integration), README, requirements.txt, deploy/stt-service.service

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

tests/test_wyoming.py

@@ -0,0 +1,62 @@
+import asyncio
+
+import numpy as np
+import pytest
+
+pytest.importorskip("wyoming")
+
+from wyoming.asr import Transcribe, Transcript  # noqa: E402
+from wyoming.audio import AudioChunk, AudioStart, AudioStop  # noqa: E402
+from wyoming.client import AsyncTcpClient  # noqa: E402
+from wyoming.info import Describe, Info  # noqa: E402
+
+import stt_service as service  # noqa: E402
+import stt_wyoming  # noqa: E402
+from conftest import FakeEngine, tone  # noqa: E402
+
+
+async def _with_server(scenario):
+    engine = FakeEngine()
+    worker = service.TranscriptionWorker(engine)
+    server = await stt_wyoming.start_server(worker, "127.0.0.1", 0)
+    port = server._server.sockets[0].getsockname()[1]
+    try:
+        return await scenario(port), engine
+    finally:
+        await server.stop()
+        worker.shutdown()
+
+
+def test_describe_returns_asr_info():
+    async def scenario(port):
+        async with AsyncTcpClient("127.0.0.1", port) as client:
+            await client.write_event(Describe().event())
+            return Info.from_event(await client.read_event())
+
+    info, _ = asyncio.run(_with_server(scenario))
+    assert info.asr[0].models[0].name == "fake"
+    assert "de" in info.asr[0].models[0].languages
+
+
+def test_transcribe_converts_audio_format():
+    """HA schickt 16 kHz mono; hier absichtlich 22,05 kHz stereo → Konvertierung."""
+    rate = 22050
+    left = tone(1.0, rate=rate)
+    stereo = np.stack([left, left], axis=1).reshape(-1)
+    pcm = (stereo * 32767).astype("<i2").tobytes()
+
+    async def scenario(port):
+        async with AsyncTcpClient("127.0.0.1", port) as client:
+            await client.write_event(Transcribe(language="de-DE", transcript_names=["Wohnzimmer"]).event())
+            await client.write_event(AudioStart(rate=rate, width=2, channels=2).event())
+            step = 4410 * 2
+            for i in range(0, len(pcm), step):
+                await client.write_event(AudioChunk(rate=rate, width=2, channels=2, audio=pcm[i:i + step]).event())
+            await client.write_event(AudioStop().event())
+            return Transcript.from_event(await client.read_event())
+
+    transcript, engine = asyncio.run(_with_server(scenario))
+    assert transcript.text == "audio 1.0s" and transcript.language == "de"
+    call = engine.calls[0]
+    assert call["hotwords"] == "Wohnzimmer" and call["language"] == "de-DE"
+    assert abs(call["samples"] - 16000) < 50