feat: add session history with auto-save

- Add Rust backend for session persistence using tauri-plugin-store
- Create SessionHistoryPanel component for browsing saved sessions
- Implement debounced auto-save (2s delay) when messages are added
- Add session search, resume, and delete functionality
- Add clock icon button in StatusBar to access session history

Closes #14

src-tauri/src/lib.rs

@@ -3,6 +3,7 @@ mod bridge_manager;
 mod commands;
 mod config;
 mod notifications;
+mod sessions;
 mod stats;
 mod temp_manager;
 mod tray;
@@ -16,6 +17,7 @@ use bridge_manager::create_shared_bridge_manager;
 use commands::load_saved_achievements;
 use commands::*;
 use notifications::*;
+use sessions::*;
 use tauri::Manager;
 use temp_manager::create_shared_temp_manager;
 use tray::{setup_tray, should_minimize_to_tray};
@@ -102,6 +104,12 @@ pub fn run() {
             cleanup_all_temp_files,
             cleanup_orphaned_temp_files,
             get_file_size,
+            list_sessions,
+            save_session,
+            load_session,
+            delete_session,
+            search_sessions,
+            clear_all_sessions,
         ])
         .run(tauri::generate_context!())
         .expect("error while running tauri application");