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>

src-tauri/src/lib.rs

@@ -1,8 +1,10 @@
 pub mod commands;
 pub mod db;
+pub mod sidecar;
 pub mod state;
 
 use commands::project::{create_project, get_project, list_projects};
+use commands::transcribe::transcribe_file;
 
 #[cfg_attr(mobile, tauri::mobile_entry_point)]
 pub fn run() {
@@ -12,6 +14,7 @@ pub fn run() {
             create_project,
             get_project,
             list_projects,
+            transcribe_file,
         ])
         .run(tauri::generate_context!())
         .expect("error while running tauri application");