feat: implement auto lightweight mode timer functionality

This commit implements the automatic lightweight mode feature with timer functionality:

- Rename configuration properties from auto_enter_lite_mode to enable_auto_light_weight_mode and auto_enter_lite_mode_delay to auto_light_weight_minutes for better clarity
- Add window event listeners to detect when window is closed or gets focus
- Implement timer system to automatically enter lightweight mode after configured time
- Remove exit_lightweight_mode function as it's no longer needed with the new implementation
- Update UI components to reflect the new property names
- Add logging for lightweight mode operations
- Initialize lightweight mode based on user configuration at startup

The feature now allows users to set a timer that will automatically enter lightweight mode
after closing the main window, which can be cancelled by focusing the window again.

src-tauri/src/lib.rs

@@ -217,7 +217,6 @@ pub fn run() {
             cmd::check_media_unlock,
             // light-weight model
             cmd::entry_lightweight_mode,
-            cmd::exit_lightweight_mode,
         ]);
 
     #[cfg(debug_assertions)]