fix(auth): resetPassword 解除锁定 + 登录错误提示优化

Backend:
- password.service.ts: resetPassword 成功后调用 user.unlock()，
  清除 loginFailCount 和 lockedUntil，避免用户改密后仍无法登录

Frontend:
- api_client.dart: 401 响应提取后端真实错误消息，不再丢弃
- auth_remote_datasource.dart: loginWithPassword 直接 rethrow
  已知异常类型，避免二次包装导致消息格式混乱
- login_page.dart: 登录失败按错误类型分类提示：
  · 账户锁定 → AlertDialog + "找回密码"按钮
  · 还有尝试机会 → SnackBar(橙色) + "找回密码"Action
  · 其他错误 → 普通 SnackBar

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/services/auth-service/src/application/services/password.service.ts

@@ -63,8 +63,9 @@ export class PasswordService {
       throw new NotFoundException('用户不存在');
     }
 
-    // 修改密码
+    // 修改密码，同时解除锁定（短信验证身份已通过，清除失败计数）
     await user.changePassword(dto.newPassword);
+    user.unlock();
     await this.userRepository.save(user);
   }
 

frontend/mining-app/lib/core/network/api_client.dart

@@ -146,7 +146,15 @@ class ApiClient {
       case DioExceptionType.badResponse:
         final statusCode = e.response?.statusCode;
         if (statusCode == 401) {
-          return UnauthorizedException();
+          final data = e.response?.data;
+          final error = data is Map ? data['error'] : null;
+          final rawMsg = error is Map ? error['message'] : null;
+          final msg = rawMsg is String
+              ? rawMsg
+              : (rawMsg is List && rawMsg.isNotEmpty)
+                  ? rawMsg[0].toString()
+                  : null;
+          return UnauthorizedException(msg ?? '未授权，请重新登录');
         }
         if (statusCode == 403) {
           final data = e.response?.data;

frontend/mining-app/lib/data/datasources/remote/auth_remote_datasource.dart

@@ -138,6 +138,7 @@ class AuthRemoteDataSourceImpl implements AuthRemoteDataSource {
       );
       return AuthResult.fromJson(response.data as Map<String, dynamic>);
     } catch (e) {
+      if (e is UnauthorizedException || e is ForbiddenException || e is NetworkException) rethrow;
       throw ServerException(e.toString());
     }
   }

frontend/mining-app/lib/presentation/pages/auth/login_page.dart

@@ -3,6 +3,7 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:go_router/go_router.dart';
 import '../../../core/router/routes.dart';
 import '../../../core/constants/app_colors.dart';
+import '../../../core/error/exceptions.dart';
 import '../../providers/user_providers.dart';
 
 class LoginPage extends ConsumerStatefulWidget {
@@ -45,9 +46,55 @@ class _LoginPageState extends ConsumerState<LoginPage> {
         context.go(Routes.contribution);
       }
     } catch (e) {
-      if (mounted) {
+      if (!mounted) return;
+      final message = e is UnauthorizedException
+          ? e.message
+          : e is ForbiddenException
+              ? e.message
+              : e is NetworkException
+                  ? e.message
+                  : e.toString().replaceFirst(RegExp(r'^[A-Za-z]+Exception:\s*'), '');
+
+      if (message.contains('锁定')) {
+        // 账户已锁定 → 弹窗 + 找回密码
+        showDialog<void>(
+          context: context,
+          builder: (ctx) => AlertDialog(
+            title: const Text('账户已锁定'),
+            content: Text(message),
+            actions: [
+              TextButton(
+                onPressed: () => Navigator.pop(ctx),
+                child: Text('知道了', style: TextStyle(color: AppColors.textSecondaryOf(context))),
+              ),
+              ElevatedButton(
+                onPressed: () {
+                  Navigator.pop(ctx);
+                  context.push(Routes.forgotPassword);
+                },
+                style: ElevatedButton.styleFrom(backgroundColor: _orange),
+                child: const Text('找回密码', style: TextStyle(color: Colors.white)),
+              ),
+            ],
+          ),
+        );
+      } else if (message.contains('还剩')) {
+        // 密码错误但还有机会 → SnackBar 提醒 + 找回密码入口
         ScaffoldMessenger.of(context).showSnackBar(
-          SnackBar(content: Text('登录失败: $e')),
+          SnackBar(
+            content: Text(message),
+            backgroundColor: Colors.orange.shade800,
+            duration: const Duration(seconds: 5),
+            action: SnackBarAction(
+              label: '找回密码',
+              textColor: Colors.white,
+              onPressed: () => context.push(Routes.forgotPassword),
+            ),
+          ),
+        );
+      } else {
+        ScaffoldMessenger.of(context).showSnackBar(
+          SnackBar(content: Text(message)),
         );
       }
     }