fix(mpc-service): use explicit container names for rwa services

When mpc-service joins mpc-system network, 'postgres' resolves to mpc-postgres.
Use explicit names (rwa-postgres, rwa-redis, rwa-kafka) to avoid conflicts.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

backend/services/docker-compose.yml

@@ -325,13 +325,14 @@ services:
     environment:
       - NODE_ENV=production
       - APP_PORT=3006
-      - DATABASE_URL=postgresql://${POSTGRES_USER:-rwa_user}:${POSTGRES_PASSWORD:-rwa_secure_password}@postgres:5432/rwa_mpc?schema=public
+      # 使用 rwa-postgres 而不是 postgres，避免 mpc-system 网络的 postgres 冲突
+      - DATABASE_URL=postgresql://${POSTGRES_USER:-rwa_user}:${POSTGRES_PASSWORD:-rwa_secure_password}@rwa-postgres:5432/rwa_mpc?schema=public
       - JWT_SECRET=${JWT_SECRET}
-      - REDIS_HOST=redis
+      - REDIS_HOST=rwa-redis
       - REDIS_PORT=6379
       - REDIS_PASSWORD=${REDIS_PASSWORD:-}
       - REDIS_DB=5
-      - KAFKA_BROKERS=kafka:29092
+      - KAFKA_BROKERS=rwa-kafka:29092
       - KAFKA_CLIENT_ID=mpc-service
       - KAFKA_GROUP_ID=mpc-service-group
       # MPC System - 使用 Docker 网络内部地址