improve visual feedback after operation completion

src/ui/modals.py

@@ -404,6 +404,15 @@ class ProgressScreen(Screen[None]):
         except Exception:
             pass
             
+        try:
+            menu_btn = self.query_one("#btn_main_menu", Button)
+            if status == "complete":
+                menu_btn.variant = "success"
+            else:
+                menu_btn.variant = "warning"
+        except Exception:
+            pass
+
     def show_info(self, migration_status: str, items_status: str):
         try:
             info = self.query_one("#info_container", Vertical)