...

lib/pages/login.dart

@@ -30,7 +30,9 @@ class _LoginPageState extends State<LoginPage> {
         await apiService.login(email, password);
       }
     } catch (e) {
-      setState(() => _error = e.toString());
+      if (mounted) {
+        setState(() => _error = e.toString());
+      }
     } finally {
       if (mounted) {
         setState(() => _loading = false);
@@ -38,6 +40,13 @@ class _LoginPageState extends State<LoginPage> {
     }
   }
 
+  @override
+  void dispose() {
+    _emailCtl.dispose();
+    _pwCtl.dispose();
+    super.dispose();
+  }
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(