Add HuggingFace token setting for speaker detection

- Add "Speakers" tab in Settings with HF token input field
- Include step-by-step instructions for obtaining the token
- Pass hf_token from settings through Rust → Python pipeline → diarize
- Token can also be set via HF_TOKEN environment variable as fallback
- Move skip_diarization checkbox to Speakers tab

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

python/voice_to_notes/services/diarize.py

@@ -35,7 +35,7 @@ class DiarizeService:
     def __init__(self) -> None:
         self._pipeline: Any = None
 
-    def _ensure_pipeline(self) -> Any:
+    def _ensure_pipeline(self, hf_token: str | None = None) -> Any:
         """Load the pyannote diarization pipeline (lazy)."""
         if self._pipeline is not None:
             return self._pipeline
@@ -44,7 +44,9 @@ class DiarizeService:
 
         print("[sidecar] Loading pyannote diarization pipeline...", file=sys.stderr, flush=True)
 
-        hf_token = os.environ.get("HF_TOKEN") or os.environ.get("HUGGING_FACE_HUB_TOKEN") or None
+        # Use token from argument, fall back to environment variable
+        if not hf_token:
+            hf_token = os.environ.get("HF_TOKEN") or os.environ.get("HUGGING_FACE_HUB_TOKEN") or None
 
         models = [
             "pyannote/speaker-diarization-3.1",
@@ -81,6 +83,7 @@ class DiarizeService:
         num_speakers: int | None = None,
         min_speakers: int | None = None,
         max_speakers: int | None = None,
+        hf_token: str | None = None,
     ) -> DiarizationResult:
         """Run speaker diarization on an audio file.
 
@@ -98,7 +101,7 @@ class DiarizeService:
             progress_message(request_id, 0, "loading_diarization", "Loading diarization model...")
         )
 
-        pipeline = self._ensure_pipeline()
+        pipeline = self._ensure_pipeline(hf_token=hf_token)
 
         write_message(
             progress_message(request_id, 20, "diarizing", "Running speaker diarization...")