fix(shutdown): mark shutdown as exiting to stop background tasks (#5024)

* fix(shutdown): mark shutdown as exiting to stop background tasks

- lib.rs:570 → Flag app as exiting on ExitRequested, notify proxy guard, start cleanup immediately, with fallback in Exit event
- tray/mod.rs:190 → Add unified exit checks around tray init/updates to prevent UI recreation during shutdown
- event_driven_proxy.rs:252 → Ensure proxy guard skips all restore/re-enable work (including sysproxy.exe calls) once exit flag is set

* fix(shutdown): refine exit handling and proxy guard notifications

* fix(shutdown): add guard to run shutdown routine only once per lifecycle

src-tauri/src/lib.rs

@@ -12,7 +12,7 @@ mod utils;
 #[cfg(target_os = "macos")]
 use crate::utils::window_manager::WindowManager;
 use crate::{
-    core::{handle, hotkey},
+    core::{EventDrivenProxyManager, handle, hotkey},
     process::AsyncHandler,
     utils::{resolve, server},
 };
@@ -584,11 +584,20 @@ pub fn run() {
                 }
             }
             tauri::RunEvent::Exit => {
-                // Avoid duplicate cleanup
-                if core::handle::Handle::global().is_exiting() {
-                    return;
+                let handle = core::handle::Handle::global();
+
+                if handle.is_exiting() {
+                    logging!(
+                        debug,
+                        Type::System,
+                        "Exit事件触发，但退出流程已执行，跳过重复清理"
+                    );
+                } else {
+                    logging!(debug, Type::System, "Exit事件触发，执行清理流程");
+                    handle.set_is_exiting();
+                    EventDrivenProxyManager::global().notify_app_stopping();
+                    feat::clean();
                 }
-                feat::clean();
             }
             tauri::RunEvent::WindowEvent { label, event, .. } => {
                 if label == "main" {