fix: alembic version_num 长度修复 + 前端部署配置

- env.py: 自动创建 alembic_version 表时使用 VARCHAR(255) 避免截断
- docker-compose: 添加 frontend nginx 服务 + alembic 挂载
- nginx.conf: SPA 路由 + API 代理

docker-compose.yml

@@ -6,7 +6,7 @@ services:
       POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:?POSTGRES_PASSWORD 未设置}
       POSTGRES_DB: ${POSTGRES_DB:-football}
     ports:
-      - "${POSTGRES_PORT:-5432}:5432"
+      - "${POSTGRES_PORT:-5433}:5432"
     volumes:
       - pgdata:/var/lib/postgresql/data
     healthcheck:
@@ -26,6 +26,18 @@ services:
         condition: service_healthy
     volumes:
       - ./src:/app/src
+      - ./alembic:/app/alembic
+      - ./alembic.ini:/app/alembic.ini
+
+  frontend:
+    image: nginx:alpine
+    ports:
+      - "${FRONTEND_PORT:-3000}:80"
+    volumes:
+      - ./frontend/dist:/usr/share/nginx/html
+      - ./frontend/nginx.conf:/etc/nginx/conf.d/default.conf:ro
+    depends_on:
+      - api
 
 volumes:
   pgdata: