Feat: Chatterbox-Klon-Referenz hochladen (eigene Stimme via ElevenLabs → lokal unbegrenzt klonen)

Sidecar: /reference (POST Upload → 24kHz-Mono-WAV via PyAV/faster-whisper, kein System-ffmpeg;
GET/DELETE). Chatterbox nutzt aktive Referenz (active.txt, überlebt Restart). Backend: /api/voice/
reference-Proxy. Picker (Chatterbox): „Referenz-Stimme hochladen (mp3/wav)" → setzt Stimme auf
»deine Referenz«. Ermöglicht den User-Plan: Stimme besorgen → EL erzeugen → Chatterbox klont.

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

backend/routers/voice.py

@@ -79,6 +79,42 @@ async def voice_stt(audio: UploadFile = File(...), language: str = Form(default=
         raise HTTPException(502, f"STT fehlgeschlagen: {exc}")
 
 
+@router.post("/voice/reference")
+async def voice_set_reference(audio: UploadFile = File(...)) -> dict:
+    """Klon-Referenz (z.B. ElevenLabs-Erzeugnis) hochladen → Chatterbox nutzt sie. Proxy → Sidecar."""
+    data = await audio.read()
+    if not data:
+        raise HTTPException(400, "Leeres Audio.")
+    files = {"audio": (audio.filename or "ref.wav", data, audio.content_type or "audio/mpeg")}
+    try:
+        async with httpx.AsyncClient(timeout=_TIMEOUT) as client:
+            r = await client.post(f"{VOICE_SERVICE_URL}/reference", files=files)
+            r.raise_for_status()
+            return r.json()
+    except httpx.HTTPError as exc:
+        raise HTTPException(502, f"Referenz-Upload fehlgeschlagen: {exc}")
+
+
+@router.get("/voice/reference")
+def voice_get_reference() -> dict:
+    try:
+        r = httpx.get(f"{VOICE_SERVICE_URL}/reference", timeout=httpx.Timeout(8.0))
+        r.raise_for_status()
+        return r.json()
+    except Exception as exc:  # noqa: BLE001
+        return {"active": False, "error": str(exc)}
+
+
+@router.delete("/voice/reference")
+def voice_clear_reference() -> dict:
+    try:
+        r = httpx.delete(f"{VOICE_SERVICE_URL}/reference", timeout=httpx.Timeout(8.0))
+        r.raise_for_status()
+        return r.json()
+    except httpx.HTTPError as exc:
+        raise HTTPException(502, f"Löschen fehlgeschlagen: {exc}")
+
+
 @router.post("/voice/tts")
 async def voice_tts(body: TTSIn) -> Response:
     """Text → Sprache (Proxy auf Sidecar /tts), liefert WAV-Bytes."""