[FIX] linux: correct Wayland window buffer mismatch by setAsFreameless()

Wayland (Hyprland, Sway, etc.) compositors misreport window buffer geometry
when using transparent + hidden titlebar settings.

This causes Flutter to render outside the actual visible region
and the debug banner to be cropped offscreen.

Calling windowManager.setAsFrameless() once after window creation
forces compositor to reconfigure the surface and align buffer size
with the visible client area.

No effect on X11, Windows, or macOS.

Signed-off-by: Texas0295 <kimura@texas0295.top>

lib/main.dart

@@ -120,13 +120,25 @@ void main() async {
       windowButtonVisibility: true,
     );
     windowManager.waitUntilReadyToShow(windowOptions, () async {
+      final env = Platform.environment;
+      final isWayland = env.containsKey('WAYLAND_DISPLAY');
+
+      if (isWayland) {
+        try {
+          await windowManager.setAsFrameless();
+        } catch (e) {
+          debugPrint('[Wayland] setAsFrameless failed: $e');
+        }
+      }
+      await windowManager.setAsFrameless();
       await windowManager.setMinimumSize(defaultSize);
       await windowManager.show();
       await windowManager.focus();
       final opacity = prefs.getDouble(kAppWindowOpacity) ?? 1.0;
       await windowManager.setOpacity(opacity);
       talker.info(
-        "[SplashScreen] Desktop window is ready with size: ${initialSize.width}x${initialSize.height}",
+        "[SplashScreen] Desktop window is ready with size: ${initialSize.width}x${initialSize.height}"
+        "${isWayland ? " (Wayland frameless fix applied)" : ""}",
       );
     });
   }