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_endpoints_e2e.py

@@ -0,0 +1,96 @@
+import json
+
+from fastapi.testclient import TestClient
+
+import app.dependencies as deps
+from app.main import app
+from tests.conftest import loopback_output
+
+client = TestClient(app)
+
+
+def test_speak_loopback_collects_chunks():
+    # piper-Stub liefert b"" -> kein Netzcall; Loopback sammelt den Chunk.
+    resp = client.post(
+        "/api/speak",
+        json={"text": "Hallo Welt", "tts_provider": "piper", "output_endpoint": "loopback"},
+    )
+    assert resp.status_code == 200
+    assert resp.headers["X-Output-Endpoint"] == "loopback"
+    assert resp.headers["X-TTS-Provider"] == "piper"
+    assert len(loopback_output().chunks) == 1
+
+
+def test_unknown_endpoint_returns_422():
+    resp = client.post(
+        "/api/speak",
+        json={"text": "x", "tts_provider": "piper", "output_endpoint": "gibtsnicht"},
+    )
+    assert resp.status_code == 422
+    assert "gibtsnicht" in resp.json()["detail"]
+
+
+def test_unknown_provider_returns_422():
+    resp = client.post("/api/speak", json={"text": "x", "tts_provider": "gibtsnicht"})
+    assert resp.status_code == 422
+
+
+def test_session_route_applies():
+    client.post(
+        "/api/sessions/s1/route",
+        json={"tts_provider": "piper", "output_endpoint": "loopback"},
+    )
+    resp = client.post("/api/speak?session_id=s1", json={"text": "hallo"})
+    assert resp.status_code == 200
+    assert resp.headers["X-Output-Endpoint"] == "loopback"
+    assert resp.headers["X-TTS-Provider"] == "piper"
+
+
+def test_chat_per_request_override_and_loopback(monkeypatch):
+    class StubLLM:
+        async def complete(self, text, session_id=None):
+            return "Mir geht es gut, danke."
+
+    class StubTTS:
+        async def synthesize(self, text, voice=None, audio_format="pcm"):
+            return b"AUDIO"
+
+    monkeypatch.setitem(deps.LLM_REGISTRY, "stub", lambda s: StubLLM())
+    monkeypatch.setitem(deps.TTS_REGISTRY, "stub", lambda s: StubTTS())
+
+    resp = client.post(
+        "/api/chat?debug=true",
+        json={
+            "text": "Wie geht es dir?",
+            "llm_provider": "stub",
+            "tts_provider": "stub",
+            "output_endpoint": "loopback",
+        },
+    )
+    assert resp.status_code == 200
+    body = resp.json()
+    assert body["route"]["llm_provider"] == "stub"
+    assert body["route"]["output_endpoint"] == "loopback"
+    assert body["trace"]["semantic_response"] == "Mir geht es gut, danke."
+    assert loopback_output().chunks[0].data == b"AUDIO"
+
+
+def test_transcribe_local_provider():
+    files = {"file": ("a.wav", b"RIFFdata", "audio/wav")}
+    data = {"stt_provider": "faster-whisper"}
+    resp = client.post("/api/transcribe", data=data, files=files)
+    assert resp.status_code == 200
+    body = resp.json()
+    assert body["route"]["stt_provider"] == "faster-whisper"
+    assert body["trace"]["raw_transcript"] == "[local transcription placeholder]"
+
+
+def test_config_endpoint_exposes_no_secrets():
+    resp = client.get("/api/config")
+    assert resp.status_code == 200
+    body = resp.json()
+    assert "piper" in body["available"]["tts_providers"]
+    assert "loopback" in {e["kind"] for e in body["available"]["output_endpoints"]}
+    # Keine echten Secrets im Body.
+    assert "sk-or-" not in json.dumps(body)
+    assert set(body["secrets"].keys()) == {"openrouter_api_key_set"}