feat(tray): hide window on close and refine tray UX; simplify icon handling

- Intercept CloseRequested to hide instead of exit (keep tray resident)
- Add 'Open Main' menu item; left-click shows menu; reduce tray click logs
- Use default app icon for tray for now; remove runtime PNG decoding
- Drop unused image dependency and tray resources entry
- Prepare path for future macOS template icon under icons/tray/macos

src-tauri/src/lib.rs

@@ -9,7 +9,7 @@ mod store;
 use store::AppState;
 use tauri::{
     menu::{CheckMenuItem, Menu, MenuBuilder, MenuItem},
-    tray::{MouseButton, MouseButtonState, TrayIconBuilder, TrayIconEvent},
+    tray::{TrayIconBuilder, TrayIconEvent},
 };
 use tauri::{Emitter, Manager};
 
@@ -312,7 +312,8 @@ pub fn run() {
             // 创建动态托盘菜单
             let menu = create_tray_menu(&app.handle(), &app_state)?;
 
-            let _tray = TrayIconBuilder::with_id("main")
+            // 构建托盘
+            let mut tray_builder = TrayIconBuilder::with_id("main")
                 .on_tray_icon_event(|_tray, event| match event {
                     // 左键点击已通过 show_menu_on_left_click(true) 打开菜单，这里不再额外处理
                     TrayIconEvent::Click { .. } => {}
@@ -322,9 +323,12 @@ pub fn run() {
                 .on_menu_event(|app, event| {
                     handle_tray_menu_event(app, &event.id.0);
                 })
-                .icon(app.default_window_icon().unwrap().clone())
-                .show_menu_on_left_click(true)
-                .build(app)?;
+                .show_menu_on_left_click(true);
+
+            // 统一使用应用默认图标；待托盘模板图标就绪后再启用
+            tray_builder = tray_builder.icon(app.default_window_icon().unwrap().clone());
+
+            let _tray = tray_builder.build(app)?;
             // 将同一个实例注入到全局状态，避免重复创建导致的不一致
             app.manage(app_state);
             Ok(())