fix(trading,auth): add parent .env path for shared JWT_SECRET

Both services need to read JWT_SECRET from the shared .env file
in the parent directory (backend/services/.env).

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/services/auth-service/src/app.module.ts

@@ -9,7 +9,7 @@ import { InfrastructureModule } from './infrastructure/infrastructure.module';
     // 配置模块
     ConfigModule.forRoot({
       isGlobal: true,
-      envFilePath: ['.env.local', '.env'],
+      envFilePath: ['.env.local', '.env', '../.env'],
     }),
 
     // 限流模块

backend/services/trading-service/src/app.module.ts

@@ -13,7 +13,11 @@ import { JwtAuthGuard } from './shared/guards/jwt-auth.guard';
   imports: [
     ConfigModule.forRoot({
       isGlobal: true,
-      envFilePath: [`.env.${process.env.NODE_ENV || 'development'}`, '.env'],
+      envFilePath: [
+        `.env.${process.env.NODE_ENV || 'development'}`,
+        '.env',
+        '../.env', // 父目录共享 .env
+      ],
       ignoreEnvFile: false,
     }),
     InfrastructureModule,