feat: 优化警告

mobile/lib/features/servers/server_form_page.dart

@@ -508,7 +508,7 @@ class _CardSection extends StatelessWidget {
                     ),
                   ),
                 ),
-                if (trailing != null) trailing!,
+                ?trailing,
               ],
             ),
             if (children.isNotEmpty) const SizedBox(height: 14),
@@ -1096,55 +1096,6 @@ class _ProxyField extends StatelessWidget {
   }
 }
 
-class _DropdownField<T> extends StatelessWidget {
-  const _DropdownField({
-    required this.label,
-    required this.value,
-    required this.items,
-    required this.onChanged,
-    this.validator,
-    this.icon,
-    this.enabled = true,
-    this.emptyText,
-    this.selectedItemBuilder,
-  });
-
-  final String label;
-  final T? value;
-  final List<DropdownMenuItem<T>> items;
-  final ValueChanged<T?> onChanged;
-  final String? Function(T?)? validator;
-  final IconData? icon;
-  final bool enabled;
-  final String? emptyText;
-  final DropdownButtonBuilder? selectedItemBuilder;
-
-  @override
-  Widget build(BuildContext context) {
-    return _LabeledBlock(
-      label: label,
-      child: DropdownButtonFormField<T>(
-        initialValue: value,
-        isExpanded: true,
-        items: items,
-        onChanged: enabled ? onChanged : null,
-        validator: validator,
-        hint: emptyText == null
-            ? null
-            : Text(
-                emptyText!,
-                overflow: TextOverflow.ellipsis,
-                style: const TextStyle(color: _FormColors.label),
-              ),
-        selectedItemBuilder: selectedItemBuilder,
-        icon: Icon(icon ?? Icons.keyboard_arrow_down, color: _FormColors.label),
-        style: const TextStyle(color: _FormColors.text, fontSize: 15),
-        decoration: _fieldDecoration(),
-      ),
-    );
-  }
-}
-
 class _PickerField extends StatelessWidget {
   const _PickerField({
     required this.label,

mobile/lib/features/servers/servers_tab.dart

@@ -44,6 +44,16 @@ class _ServersTabState extends ConsumerState<ServersTab> {
     super.dispose();
   }
 
+  void toggleServerExpanded(String id) {
+    setState(() {
+      if (_expandedServerIds.contains(id)) {
+        _expandedServerIds.remove(id);
+      } else {
+        _expandedServerIds.add(id);
+      }
+    });
+  }
+
   Future<void> _refresh() async {
     await refreshServerSharedData(ref);
   }
@@ -782,15 +792,7 @@ class _ServerCard extends StatelessWidget {
                         ? Icons.keyboard_arrow_up
                         : Icons.keyboard_arrow_down,
                     highlighted: expanded,
-                    onTap: () {
-                      state.setState(() {
-                        if (expanded) {
-                          state._expandedServerIds.remove(server.id);
-                        } else {
-                          state._expandedServerIds.add(server.id);
-                        }
-                      });
-                    },
+                    onTap: () => state.toggleServerExpanded(server.id),
                   ),
                 ],
               ),

mobile/lib/l10n/app_localizations.dart

@@ -1,4 +1,3 @@
-import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
 
 import 'strings_en.dart';

mobile/test/features/servers/servers_tab_test.dart

@@ -22,6 +22,7 @@ class _FakeRepository implements ServerRepository {
     this.hosts = const [],
     this.groups = const [],
     this.fetchError,
+    // ignore: unused_element_parameter
     this.groupFetchError,
     SshConnectionConfig? config,
     this.sshError,