Extract and apply StartupWMClass for proper taskbar icons

Parse StartupWMClass from embedded .desktop entries during analysis,
store in DB, include in generated .desktop files. Detail view shows
an editable WM class field with apply button for manual override.

src/ui/detail_view.rs

@@ -1033,6 +1033,28 @@ fn build_system_tab(record: &AppImageRecord, db: &Rc<Database>, toast_overlay: &
     });
     integration_group.add(&autostart_row);
 
+    // StartupWMClass row with editable override
+    let wm_class_row = adw::EntryRow::builder()
+        .title("StartupWMClass")
+        .text(record.startup_wm_class.as_deref().unwrap_or(""))
+        .show_apply_button(true)
+        .build();
+    let db_wm = db.clone();
+    let record_id_wm = record.id;
+    let toast_wm = toast_overlay.clone();
+    wm_class_row.connect_apply(move |row| {
+        let text = row.text().to_string();
+        let value = if text.is_empty() { None } else { Some(text.as_str()) };
+        match db_wm.set_startup_wm_class(record_id_wm, value) {
+            Ok(()) => toast_wm.add_toast(adw::Toast::new("WM class updated")),
+            Err(e) => {
+                log::error!("Failed to set WM class: {}", e);
+                toast_wm.add_toast(adw::Toast::new("Failed to update WM class"));
+            }
+        }
+    });
+    integration_group.add(&wm_class_row);
+
     inner.append(&integration_group);
 
     // Version Rollback group