feat(mobile): 服务器列表页与可注入仓库

将 ServerRepository 重构为接口，由 ApiServerRepository 提供
实际网络与解密实现，使列表页 widget 测试可以注入伪仓库覆盖
空列表、错误重试、连接失败 SnackBar 与登出按钮路径。

mobile/lib/app.dart

@@ -124,7 +124,7 @@ class _EasyNodeAppState extends State<EasyNodeApp> {
     Widget home;
     if (_session != null && _apiClient != null && _publicKeyPem != null) {
       home = ServerListPage(
-        repository: ServerRepository(
+        repository: ApiServerRepository(
           apiClient: _apiClient!,
           publicKeyPem: _publicKeyPem!,
         ),

mobile/lib/features/servers/server_repository.dart

@@ -9,9 +9,17 @@ import '../../core/crypto/rsa_crypto.dart';
 import '../terminal/ssh_connection_config.dart';
 import 'server_model.dart';
 
-/// Backs the server list page and the connect action.
-class ServerRepository {
-  ServerRepository({
+/// Backs the server list page and the connect action. The interface lets
+/// widget tests inject a fake without touching real HTTP / RSA code.
+abstract class ServerRepository {
+  Future<List<ServerModel>> fetchHosts();
+  Future<SshConnectionConfig> fetchSshConfig(String hostId);
+}
+
+/// Default [ServerRepository] backed by [ApiClient] and the RSA public key
+/// fetched at login time.
+class ApiServerRepository implements ServerRepository {
+  ApiServerRepository({
     required ApiClient apiClient,
     required String publicKeyPem,
     RsaCrypto? rsa,
@@ -27,6 +35,7 @@ class ServerRepository {
   final Random _random;
 
   /// Fetch the host list. Server returns `{ data: [host...] }`.
+  @override
   Future<List<ServerModel>> fetchHosts() async {
     final response = await _api.getJson('/host-list');
     final raw = response['data'];
@@ -46,6 +55,7 @@ class ServerRepository {
   /// 5. Return a strongly typed [SshConnectionConfig].
   ///
   /// The temporary key and decrypted payload live only inside this method.
+  @override
   Future<SshConnectionConfig> fetchSshConfig(String hostId) async {
     final keyBytes = _randomBytes(32);
     final encryptedKey = _rsa.encryptTemporaryKey(_publicKeyPem, keyBytes);
@@ -90,7 +100,7 @@ class ServerRepository {
     return bytes;
   }
 
-  /// Expose so [ServerRepository] can be JSON-serialized in widget tests.
+  /// Expose so [ApiServerRepository] can be JSON-serialized in widget tests.
   // ignore: unused_element
   String _debugBase64Bytes(Uint8List bytes) => base64Encode(bytes);
 }

mobile/test/features/servers/server_list_page_test.dart

@@ -0,0 +1,151 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:mobile/features/auth/auth_session.dart';
+import 'package:mobile/features/servers/server_list_page.dart';
+import 'package:mobile/features/servers/server_model.dart';
+import 'package:mobile/features/servers/server_repository.dart';
+import 'package:mobile/features/terminal/ssh_connection_config.dart';
+
+class _FakeRepository implements ServerRepository {
+  _FakeRepository({
+    this.hosts = const [],
+    this.fetchError,
+    SshConnectionConfig? config,
+    this.sshError,
+  }) : config = config ?? _defaultConfig;
+
+  List<ServerModel> hosts;
+  Object? fetchError;
+  SshConnectionConfig config;
+  Object? sshError;
+  int connectCalls = 0;
+
+  static const _defaultConfig = SshConnectionConfig(
+    hostId: 'h1',
+    name: 'srv',
+    host: '10.0.0.2',
+    port: 22,
+    username: 'root',
+    authType: 'password',
+    password: 'pwd',
+    privateKey: '',
+    passphrase: '',
+  );
+
+  @override
+  Future<List<ServerModel>> fetchHosts() async {
+    if (fetchError != null) throw fetchError!;
+    return hosts;
+  }
+
+  @override
+  Future<SshConnectionConfig> fetchSshConfig(String hostId) async {
+    connectCalls++;
+    if (sshError != null) throw sshError!;
+    return config;
+  }
+}
+
+const _session = AuthSession(
+  serverAddress: 'https://example.com',
+  username: 'root',
+  token: 't',
+  deviceId: 'd',
+);
+
+ServerModel _server({String id = 'h1', bool canConnect = true}) {
+  return ServerModel.fromJson({
+    'id': id,
+    'name': 'srv-$id',
+    'host': '10.0.0.2',
+    'port': 22,
+    'username': 'root',
+    'authType': 'password',
+    'group': '',
+    'tag': const [],
+    'expired': !canConnect,
+    'isConfig': canConnect,
+  });
+}
+
+Widget _wrap(Widget child) => MaterialApp(home: child);
+
+void main() {
+  testWidgets('shows empty state when host list is empty', (tester) async {
+    final repo = _FakeRepository(hosts: const []);
+    await tester.pumpWidget(_wrap(ServerListPage(
+      repository: repo,
+      session: _session,
+      onLogout: () {},
+    )));
+    await tester.pumpAndSettle();
+
+    expect(find.textContaining('暂无服务器'), findsOneWidget);
+  });
+
+  testWidgets('renders one tile per host with connect button', (tester) async {
+    final repo = _FakeRepository(hosts: [
+      _server(id: 'h1'),
+      _server(id: 'h2', canConnect: false),
+    ]);
+    await tester.pumpWidget(_wrap(ServerListPage(
+      repository: repo,
+      session: _session,
+      onLogout: () {},
+    )));
+    await tester.pumpAndSettle();
+
+    expect(find.byKey(const Key('server-h1')), findsOneWidget);
+    expect(find.byKey(const Key('server-h2')), findsOneWidget);
+    expect(find.text('连接'), findsOneWidget);
+    expect(find.text('未配置'), findsOneWidget);
+  });
+
+  testWidgets('shows error and retry button when fetch fails', (tester) async {
+    final repo = _FakeRepository(fetchError: Exception('boom'));
+    await tester.pumpWidget(_wrap(ServerListPage(
+      repository: repo,
+      session: _session,
+      onLogout: () {},
+    )));
+    await tester.pumpAndSettle();
+
+    expect(find.textContaining('boom'), findsOneWidget);
+    expect(find.text('重试'), findsOneWidget);
+  });
+
+  testWidgets('shows snackbar when fetchSshConfig fails', (tester) async {
+    final repo = _FakeRepository(
+      hosts: [_server(id: 'h1')],
+      sshError: Exception('nope'),
+    );
+    await tester.pumpWidget(_wrap(ServerListPage(
+      repository: repo,
+      session: _session,
+      onLogout: () {},
+    )));
+    await tester.pumpAndSettle();
+
+    await tester.tap(find.text('连接'));
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 100));
+
+    expect(repo.connectCalls, 1);
+    expect(find.textContaining('获取 SSH 参数失败'), findsOneWidget);
+  });
+
+  testWidgets('logout button calls onLogout', (tester) async {
+    var loggedOut = 0;
+    final repo = _FakeRepository(hosts: const []);
+    await tester.pumpWidget(_wrap(ServerListPage(
+      repository: repo,
+      session: _session,
+      onLogout: () => loggedOut++,
+    )));
+    await tester.pumpAndSettle();
+
+    await tester.tap(find.byTooltip('退出登录'));
+    await tester.pump();
+    expect(loggedOut, 1);
+  });
+}