chore(docker): expose postgres port to host

Map container port 5432 to host port 50001 for external database access

docker-compose.yml

@@ -7,6 +7,8 @@ services:
       POSTGRES_PASSWORD: pokopia
     volumes:
       - postgres18_data:/var/lib/postgresql
+    ports:
+      - "50001:5432"          # 添加这一行：宿主机 50001 → 容器 5432
     healthcheck:
       test: ["CMD-SHELL", "pg_isready -U pokopia -d pokopia"]
       interval: 5s