Show updates-available banner in Installed view

src/window.rs

@@ -1374,6 +1374,10 @@ impl DriftwoodWindow {
                 page.set_needs_attention(count > 0);
             }
         }
+        // Also update the banner in the Installed view
+        if let Some(library_view) = self.imp().library_view.get() {
+            library_view.set_update_count(count);
+        }
     }
 
     fn start_file_watcher(&self) {