Fix auth login button state and appearance

lib/views/auth_view.dart

@@ -19,6 +19,11 @@ class _AuthViewState extends State<AuthView> {
   @override
   void initState() {
     super.initState();
+    _tokenController.addListener(() {
+      setState(() {
+        // Update button state when text changes
+      });
+    });
     WidgetsBinding.instance.addPostFrameCallback((_) {
       _focusNode.requestFocus();
     });
@@ -111,12 +116,17 @@ class _AuthViewState extends State<AuthView> {
                       : _verifyToken,
                   style: ElevatedButton.styleFrom(
                     padding: const EdgeInsets.symmetric(vertical: 16),
+                    backgroundColor: Theme.of(context).colorScheme.primary,
+                    foregroundColor: Theme.of(context).colorScheme.onPrimary,
                   ),
                   child: _isLoading
-                      ? const SizedBox(
+                      ? SizedBox(
                           height: 20,
                           width: 20,
-                          child: CircularProgressIndicator(strokeWidth: 2),
+                          child: CircularProgressIndicator(
+                            strokeWidth: 2,
+                            color: Theme.of(context).colorScheme.onPrimary,
+                          ),
                         )
                       : const Text('Sign In'),
                 ),