Phase 2: Core transcription pipeline and audio playback

- Implement faster-whisper TranscribeService with word-level timestamps,
  progress reporting, and hardware auto-detection
- Wire up Rust SidecarManager for Python process lifecycle (spawn, IPC, shutdown)
- Add transcribe_file Tauri command bridging frontend to Python sidecar
- Integrate wavesurfer.js WaveformPlayer with play/pause, skip, seek controls
- Build TranscriptEditor with word-level click-to-seek and active highlighting
- Connect file import flow: prompt → asset load → transcribe → display
- Add typed tauri-bridge service with TranscriptionResult interface
- Add Python tests for hardware detection and transcription result formatting

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

python/voice_to_notes/main.py

@@ -5,7 +5,12 @@ from __future__ import annotations
 import signal
 import sys
 
-from voice_to_notes.ipc.handlers import HandlerRegistry, ping_handler
+from voice_to_notes.ipc.handlers import (
+    HandlerRegistry,
+    hardware_detect_handler,
+    make_transcribe_handler,
+    ping_handler,
+)
 from voice_to_notes.ipc.messages import ready_message
 from voice_to_notes.ipc.protocol import read_message, write_message
 
@@ -14,7 +19,9 @@ def create_registry() -> HandlerRegistry:
     """Set up the message handler registry."""
     registry = HandlerRegistry()
     registry.register("ping", ping_handler)
-    # TODO: Register transcribe, diarize, pipeline, ai, export handlers
+    registry.register("transcribe.start", make_transcribe_handler())
+    registry.register("hardware.detect", hardware_detect_handler)
+    # TODO: Register diarize, pipeline, ai, export handlers
     return registry