fix: 全服务注册 JwtStrategy + 修复微信 WxApi 未配置 crash

**后端**
- packages/common: 新增并导出 JwtStrategy（共享 Passport JWT 策略）
- 6 个服务模块（user/issuer/clearing/compliance/notification/telemetry）
  均缺少 JwtStrategy provider，导致所有受保护接口返回 500
  "Unknown authentication strategy jwt"
- 统一修复：各模块 providers 添加 JwtStrategy

**Flutter**
- welcome_page: _onWechatTap() 的 isWeChatInstalled 调用未设 WECHAT_APP_ID
  时会抛出 PlatformException，catch 后降级为"未安装"提示

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

backend/packages/common/src/index.ts

@@ -8,6 +8,9 @@ export * from './decorators/roles.decorator';
 export * from './guards/jwt-auth.guard';
 export * from './guards/roles.guard';
 
+// Strategies
+export * from './strategies/jwt.strategy';
+
 // Interceptors
 export * from './interceptors/logging.interceptor';
 export * from './interceptors/transform.interceptor';

backend/packages/common/src/strategies/jwt.strategy.ts

@@ -0,0 +1,25 @@
+import { Injectable } from '@nestjs/common';
+import { PassportStrategy } from '@nestjs/passport';
+import { ExtractJwt, Strategy } from 'passport-jwt';
+
+/**
+ * Shared JWT Passport Strategy.
+ * Register as a provider in each service module that uses JwtAuthGuard.
+ *
+ * Usage in module:
+ *   providers: [JwtStrategy, ...]
+ */
+@Injectable()
+export class JwtStrategy extends PassportStrategy(Strategy, 'jwt') {
+  constructor() {
+    super({
+      jwtFromRequest: ExtractJwt.fromAuthHeaderAsBearerToken(),
+      ignoreExpiration: false,
+      secretOrKey: process.env.JWT_ACCESS_SECRET || 'dev-access-secret',
+    });
+  }
+
+  async validate(payload: { sub: string; role: string; kycLevel: number; type: string }) {
+    return { sub: payload.sub, role: payload.role, kycLevel: payload.kycLevel };
+  }
+}

backend/services/clearing-service/src/clearing.module.ts

@@ -2,6 +2,7 @@ import { Module } from '@nestjs/common';
 import { TypeOrmModule } from '@nestjs/typeorm';
 import { PassportModule } from '@nestjs/passport';
 import { JwtModule } from '@nestjs/jwt';
+import { JwtStrategy } from '@genex/common';
 
 // Domain entities
 import { Settlement } from './domain/entities/settlement.entity';
@@ -44,6 +45,7 @@ import { AdminReportsController } from './interface/http/controllers/admin-repor
   ],
   controllers: [ClearingController, AdminFinanceController, AdminReportsController],
   providers: [
+    JwtStrategy,
     // Repository DI bindings (interface -> implementation)
     { provide: SETTLEMENT_REPOSITORY, useClass: SettlementRepository },
     { provide: REFUND_REPOSITORY, useClass: RefundRepository },

backend/services/compliance-service/src/compliance.module.ts

@@ -2,6 +2,7 @@ import { Module } from '@nestjs/common';
 import { TypeOrmModule } from '@nestjs/typeorm';
 import { PassportModule } from '@nestjs/passport';
 import { JwtModule } from '@nestjs/jwt';
+import { JwtStrategy } from '@genex/common';
 
 // ─── Domain Entities ───
 import { AmlAlert } from './domain/entities/aml-alert.entity';
@@ -75,6 +76,7 @@ import { AdminInsuranceController } from './interface/http/controllers/admin-ins
     AdminInsuranceController,
   ],
   providers: [
+    JwtStrategy,
     // ─── Repository DI bindings (interface → implementation) ───
     { provide: AML_ALERT_REPOSITORY, useClass: AmlAlertRepository },
     { provide: OFAC_SCREENING_REPOSITORY, useClass: OfacScreeningRepository },

backend/services/issuer-service/src/issuer.module.ts

@@ -2,6 +2,7 @@ import { Module } from '@nestjs/common';
 import { TypeOrmModule } from '@nestjs/typeorm';
 import { PassportModule } from '@nestjs/passport';
 import { JwtModule } from '@nestjs/jwt';
+import { JwtStrategy } from '@genex/common';
 
 // Domain entities
 import { Issuer } from './domain/entities/issuer.entity';
@@ -88,6 +89,7 @@ import { RolesGuard } from './interface/http/guards/roles.guard';
     CouponBatchController,
   ],
   providers: [
+    JwtStrategy,
     // Infrastructure -> Domain port binding (Repository pattern)
     { provide: ISSUER_REPOSITORY, useClass: IssuerRepository },
     { provide: COUPON_REPOSITORY, useClass: CouponRepository },

backend/services/notification-service/src/notification.module.ts

@@ -2,6 +2,7 @@ import { Module } from '@nestjs/common';
 import { TypeOrmModule } from '@nestjs/typeorm';
 import { PassportModule } from '@nestjs/passport';
 import { JwtModule } from '@nestjs/jwt';
+import { JwtStrategy } from '@genex/common';
 
 // Domain entities
 import { Notification } from './domain/entities/notification.entity';
@@ -94,6 +95,7 @@ import { DeviceTokenController } from './interface/http/controllers/device-token
     DeviceTokenController,
   ],
   providers: [
+    JwtStrategy,
     // Infrastructure -> Domain repository binding
     { provide: NOTIFICATION_REPOSITORY, useClass: NotificationRepository },
     { provide: ANNOUNCEMENT_REPOSITORY, useClass: AnnouncementRepositoryImpl },

backend/services/telemetry-service/src/telemetry.module.ts

@@ -3,6 +3,7 @@ import { TypeOrmModule } from '@nestjs/typeorm';
 import { JwtModule } from '@nestjs/jwt';
 import { PassportModule } from '@nestjs/passport';
 import { ScheduleModule } from '@nestjs/schedule';
+import { JwtStrategy } from '@genex/common';
 
 // Domain entities
 import { TelemetryEvent } from './domain/entities/telemetry-event.entity';
@@ -72,6 +73,7 @@ import { HealthController } from './interface/http/controllers/health.controller
     HealthController,
   ],
   providers: [
+    JwtStrategy,
     { provide: TELEMETRY_EVENT_REPOSITORY, useClass: TelemetryEventRepository },
     { provide: ONLINE_SNAPSHOT_REPOSITORY, useClass: OnlineSnapshotRepository },
     { provide: DAILY_ACTIVE_STATS_REPOSITORY, useClass: DailyActiveStatsRepository },

backend/services/user-service/src/user.module.ts

@@ -2,6 +2,7 @@ import { Module } from '@nestjs/common';
 import { TypeOrmModule } from '@nestjs/typeorm';
 import { JwtModule } from '@nestjs/jwt';
 import { PassportModule } from '@nestjs/passport';
+import { JwtStrategy } from '@genex/common';
 
 // Domain entities
 import { User } from './domain/entities/user.entity';
@@ -59,6 +60,7 @@ import { AdminAnalyticsController } from './interface/http/controllers/admin-ana
     AdminDashboardController, AdminUserController, AdminSystemController, AdminAnalyticsController,
   ],
   providers: [
+    JwtStrategy,
     // Infrastructure -> Domain port binding
     { provide: USER_REPOSITORY, useClass: UserRepository },
     { provide: KYC_REPOSITORY, useClass: KycRepository },

frontend/genex-mobile/lib/features/auth/presentation/pages/welcome_page.dart

@@ -78,7 +78,12 @@ class _WelcomePageState extends ConsumerState<WelcomePage> {
   // ── 微信 ─────────────────────────────────────────────────────────────────
 
   Future<void> _onWechatTap() async {
-    final installed = await _fluwx.isWeChatInstalled;
+    bool installed = false;
+    try {
+      installed = await _fluwx.isWeChatInstalled;
+    } catch (_) {
+      // WxApi not configured (WECHAT_APP_ID not provided) — treat as not installed
+    }
     if (!installed) {
       if (mounted) {
         ScaffoldMessenger.of(context).showSnackBar(