Biometric bypass on login: if enabled+registered, prompt fingerprint on open -> on success skip email/password. On fail, show grey msg and allow manual login via Masuk button

lib/auth_screen.dart

@@ -20,6 +20,7 @@ class _AuthScreenState extends State<AuthScreen> {
   bool _isLogin = true;
   bool _busy = false;
   String? _error;
+  String? _bioMsg;
 
   @override
   void initState() {
@@ -53,8 +54,12 @@ class _AuthScreenState extends State<AuthScreen> {
     if (ok) {
       final email = await widget.auth.getEmail() ?? '';
       _goToDashboard(email);
+    } else {
+      // fingerprint failed/cancelled -> let user login manually
+      setState(() {
+        _bioMsg = 'Gagal verifikasi sidik jari. Silakan masuk manual.';
+      });
     }
-    // on failure, the auth screen stays; user can tap Masuk manually
   }
 
   /// On open: if a valid session is present, go straight to Dashboard.
@@ -140,6 +145,12 @@ class _AuthScreenState extends State<AuthScreen> {
             const SizedBox(height: 8),
             if (_error != null)
               Text(_error!, style: const TextStyle(color: Colors.red)),
+            if (_bioMsg != null)
+              Padding(
+                padding: const EdgeInsets.only(bottom: 8),
+                child: Text(_bioMsg!,
+                    style: const TextStyle(color: Colors.grey)),
+              ),
             const SizedBox(height: 12),
             _busy
                 ? const CircularProgressIndicator()