Fix CSP for blob URLs + fix pyannote AudioDecoder with torchaudio patch

CSP: Add blob: to connect-src/img-src/media-src for wavesurfer.js audio
playback. Add http://tauri.localhost to default-src for devtools.

pyannote: sys.modules block didn't work — pyannote still uses AudioDecoder
unconditionally. New approach: monkey-patch Audio.__call__ in diarize.py
to use torchaudio.load() directly, bypassing the broken torchcodec path.
Patch runs once before pipeline loading.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

python/voice_to_notes/services/diarize.py

@@ -20,6 +20,36 @@ from voice_to_notes.utils.ffmpeg import get_ffmpeg_path
 from voice_to_notes.ipc.messages import progress_message
 from voice_to_notes.ipc.protocol import write_message
 
+_patched = False
+
+
+def _patch_pyannote_audio() -> None:
+    """Monkey-patch pyannote.audio.core.io.Audio to use torchaudio.
+
+    pyannote.audio has a bug where AudioDecoder (from torchcodec) is used
+    unconditionally even when torchcodec is not installed, causing NameError.
+    This replaces the Audio.__call__ method with a torchaudio-based version.
+    """
+    global _patched
+    if _patched:
+        return
+    _patched = True
+
+    try:
+        import torchaudio
+        from pyannote.audio.core.io import Audio
+
+        def _torchaudio_call(self: Audio, file: dict) -> tuple:
+            audio_path = file["audio"]
+            waveform, sample_rate = torchaudio.load(str(audio_path))
+            # pyannote expects (channel, time) tensor and sample_rate
+            return waveform, sample_rate
+
+        Audio.__call__ = _torchaudio_call  # type: ignore[assignment]
+        print("[sidecar] Patched pyannote Audio to use torchaudio", file=sys.stderr, flush=True)
+    except Exception as e:
+        print(f"[sidecar] Warning: Could not patch pyannote Audio: {e}", file=sys.stderr, flush=True)
+
 
 def _ensure_wav(file_path: str) -> tuple[str, str | None]:
     """Convert audio to 16kHz mono WAV if needed.
@@ -113,6 +143,7 @@ class DiarizeService:
         ]
 
         last_error: Exception | None = None
+        _patch_pyannote_audio()
         for model_name in models:
             try:
                 from pyannote.audio import Pipeline