revert(macos): restore Dock hiding when closing the window

This reverts commit 12f842d038.

Restore the Accessory activation policy when closing the main window or
using Cmd+W so the Dock icon disappears again. Keeping the Regular policy
avoided menu bar jitter but caused the Dock visibility regression in #8513.

Hiding the application before switching to Accessory did not reliably
eliminate the jitter. An isolated Tao 0.37.2 checkout with a native muda
menu reproduced it on macOS 27.2 without CVR or WebView. The responsible
layer remains undetermined and needs separate investigation.

The menu bar jitter reported in #8319 can still occur; this revert restores
Dock behavior and does not claim to fix that issue.

Closes #8513

src-tauri/src/feat/window.rs

@@ -316,6 +316,7 @@ pub async fn hide() {
     {
         let _ = window.hide();
     }
+    handle::Handle::global().set_activation_policy_accessory();
 }
 
 #[cfg(test)]

src-tauri/src/lib.rs

@@ -289,6 +289,9 @@ pub fn run() -> std::process::ExitCode {
         }
 
         pub fn handle_window_close(api: &tauri::WindowEvent) {
+            #[cfg(target_os = "macos")]
+            handle::Handle::global().set_activation_policy_accessory();
+
             if core::handle::Handle::global().is_exiting() {
                 return;
             }