Initial commit: Voice Assistant Gateway mit Konfig-/Routing-Fundament

- FastAPI-Gateway mit REST-Endpunkten (chat/speak/transcribe/devices/sessions/config)
- Geschichtete Konfiguration mit Profilen (local-dev/hybrid/cloud) via TOML + ENV
- Registry-Pattern + einheitliche Route-Aufloesung (Default->Profil->ENV->Session->Request)
- Device Router (strikt, Singleton) und Output-Lifecycle im Orchestrator
- OpenRouter-Adapter (STT multipart/LLM/TTS) + lokale Provider-Stubs
- Regelbasierte Pipeline (Cleaner/Spoken-Adapter/TTS-Normalizer)
- 22 automatisierte Tests; Doku: README, BEDIENUNGSANLEITUNG, Architektur
- Secrets ausschliesslich ueber Umgebung; .env und lokale config gitignored

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/test_audio_router.py

@@ -0,0 +1,43 @@
+import asyncio
+
+import pytest
+
+from app.audio.router import AudioRouter
+from app.audio.endpoints.input.local_default import LocalDefaultInput
+from app.audio.endpoints.input.bluetooth import BluetoothInput
+from app.audio.endpoints.output.local_default import LocalDefaultOutput
+from app.audio.endpoints.output.loopback import LoopbackOutput
+from app.errors import UnknownEndpointError
+
+
+def make_router():
+    return AudioRouter(
+        inputs=[LocalDefaultInput(), BluetoothInput()],
+        outputs=[LocalDefaultOutput(), LoopbackOutput()],
+    )
+
+
+def test_select_default_output():
+    router = make_router()
+    endpoint = asyncio.run(router.select_output())
+    caps = asyncio.run(endpoint.capabilities())
+    assert caps.default is True
+    assert caps.kind == "local-default"
+
+
+def test_select_output_by_kind():
+    router = make_router()
+    endpoint = asyncio.run(router.select_output("loopback"))
+    assert asyncio.run(endpoint.capabilities()).kind == "loopback"
+
+
+def test_select_input_by_id():
+    router = make_router()
+    endpoint = asyncio.run(router.select_input("local-default-mic"))
+    assert asyncio.run(endpoint.capabilities()).id == "local-default-mic"
+
+
+def test_unknown_endpoint_raises():
+    router = make_router()
+    with pytest.raises(UnknownEndpointError):
+        asyncio.run(router.select_output("does-not-exist"))