fix(tauri): restore desktop menu controls and fullscreen shortcut (#226)

## Summary
- restore the missing desktop View and Window menu controls
- use native reload and window actions where supported instead of
brittle webview-only behavior
- restore the working fullscreen keyboard shortcut while keeping the
zoom menu labels aligned with the intended desktop behavior

## Testing
- cargo check --manifest-path packages/tauri-app/src-tauri/Cargo.toml

packages/tauri-app/src-tauri/Cargo.toml

@@ -23,6 +23,7 @@ keepawake = "0.6"
 tauri-plugin-dialog = "2"
 dirs = "5"
 tauri-plugin-opener = "2"
+tauri-plugin-global-shortcut = "2"
 url = "2"
 tauri-plugin-notification = "2"