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>

app/api/transcribe.py

@@ -0,0 +1,50 @@
+from fastapi import APIRouter, File, Form, HTTPException, Query, UploadFile
+
+from app.errors import RoutingError
+from app.dependencies import (
+    resolve_route,
+    build_orchestrator,
+    resolve_input_endpoint,
+)
+
+router = APIRouter()
+
+
+@router.post("/transcribe")
+async def transcribe(
+    file: UploadFile = File(...),
+    language: str | None = Form(default=None),
+    input_endpoint: str | None = Form(default=None),
+    stt_provider: str | None = Form(default=None),
+    session_id: str | None = Query(
+        default=None,
+        description="Optional session id to apply a stored route",
+    ),
+):
+    overrides = {
+        "input_endpoint": input_endpoint,
+        "language": language,
+        "stt_provider": stt_provider,
+    }
+    route = resolve_route(session_id, overrides)
+
+    try:
+        orchestrator = build_orchestrator(route)
+        source = await resolve_input_endpoint(route)
+    except RoutingError as exc:
+        raise HTTPException(status_code=422, detail=str(exc))
+
+    content = await file.read()
+    suffix = (file.filename or "audio.wav").rsplit(".", 1)[-1].lower()
+
+    try:
+        trace = await orchestrator.transcribe_only(
+            content,
+            fmt=suffix,
+            language=route.language,
+            input=source,
+        )
+    except Exception as exc:
+        raise HTTPException(status_code=502, detail=str(exc))
+
+    return {"route": route.as_dict(), "trace": trace.model_dump()}