Support Enter to submit login

frontend/lib/pages/login_page.dart

@@ -17,8 +17,17 @@ class LoginPage extends StatefulWidget {
 class _LoginPageState extends State<LoginPage> {
   final _usernameController = TextEditingController();
   final _passwordController = TextEditingController();
+  final _passwordFocusNode = FocusNode();
   bool _isLoading = false;
 
+  @override
+  void dispose() {
+    _usernameController.dispose();
+    _passwordController.dispose();
+    _passwordFocusNode.dispose();
+    super.dispose();
+  }
+
   void _handleLogin() async {
     if (_usernameController.text.isEmpty || _passwordController.text.isEmpty) {
       ScaffoldMessenger.of(
@@ -108,6 +117,8 @@ class _LoginPageState extends State<LoginPage> {
                 // Fields
                 TextField(
                   controller: _usernameController,
+                  textInputAction: TextInputAction.next,
+                  onSubmitted: (_) => _passwordFocusNode.requestFocus(),
                   decoration: InputDecoration(
                     labelText: "Username",
                     prefixIcon: Icon(Icons.person),
@@ -119,7 +130,14 @@ class _LoginPageState extends State<LoginPage> {
                 SizedBox(height: 16),
                 TextField(
                   controller: _passwordController,
+                  focusNode: _passwordFocusNode,
                   obscureText: true,
+                  textInputAction: TextInputAction.done,
+                  onSubmitted: (_) {
+                    if (!_isLoading) {
+                      _handleLogin();
+                    }
+                  },
                   decoration: InputDecoration(
                     labelText: "Password",
                     prefixIcon: Icon(Icons.lock),