Phase 6: Llama-server manager, settings UI, packaging, and polish

- Implement LlamaManager in Rust for llama-server lifecycle: spawn with
  port allocation, health check, clean shutdown on Drop, model listing
- Add llama_start/stop/status/list_models Tauri commands
- Add load_settings/save_settings commands with JSON persistence
- Build SettingsModal with tabs for Transcription, AI Provider, Local AI
  settings (model size, device, language, API keys, provider selection)
- Wire settings into pipeline calls (model, device, language, skip diarization)
- Configure Tauri packaging: asset protocol for local audio files,
  CSP policy, bundle metadata, Linux .deb/.AppImage and Windows .msi config
- Add keyboard shortcuts: Space (play/pause), Ctrl+O (import),
  Ctrl+, (settings), Escape (close menus/modals)
- Close export dropdown on outside click
- Tests: 30 Python, 6 Rust, 0 Svelte errors

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

src-tauri/src/lib.rs

@@ -1,11 +1,14 @@
 pub mod commands;
 pub mod db;
+pub mod llama;
 pub mod sidecar;
 pub mod state;
 
 use commands::ai::{ai_chat, ai_configure, ai_list_providers};
 use commands::export::export_transcript;
 use commands::project::{create_project, get_project, list_projects};
+use commands::settings::{load_settings, save_settings};
+use commands::system::{get_data_dir, llama_list_models, llama_start, llama_status, llama_stop};
 use commands::transcribe::{run_pipeline, transcribe_file};
 
 #[cfg_attr(mobile, tauri::mobile_entry_point)]
@@ -23,6 +26,13 @@ pub fn run() {
             ai_chat,
             ai_list_providers,
             ai_configure,
+            llama_start,
+            llama_stop,
+            llama_status,
+            llama_list_models,
+            get_data_dir,
+            load_settings,
+            save_settings,
         ])
         .run(tauri::generate_context!())
         .expect("error while running tauri application");