fix: harden runtime deployment defaults

docker-compose.yml

@@ -6,10 +6,9 @@ services:
     env_file:
       - ./backend/.env
     environment:
-      - DATABASE_URL=postgresql+asyncpg://pingwatch:pingwatch123@db:5432/pingwatch
       - TZ=Asia/Shanghai
     ports:
-      - "8001:8000"
+      - "127.0.0.1:8001:8000"
     depends_on:
       db:
         condition: service_healthy
@@ -18,8 +17,7 @@ services:
     networks:
       - pingwatch-net
     cap_add:
-      - NET_RAW          # 允许 ICMP ping
-      - NET_ADMIN        # 允许原始套接字
+      - NET_RAW
 
   frontend:
     build: ./frontend
@@ -40,9 +38,9 @@ services:
     restart: unless-stopped
     environment:
       - TZ=Asia/Shanghai
-      - POSTGRES_DB=pingwatch
-      - POSTGRES_USER=pingwatch
-      - POSTGRES_PASSWORD=pingwatch123
+      - POSTGRES_DB=${POSTGRES_DB:-pingwatch}
+      - POSTGRES_USER=${POSTGRES_USER:-pingwatch}
+      - POSTGRES_PASSWORD=${POSTGRES_PASSWORD:?POSTGRES_PASSWORD must be set in backend/.env}
     volumes:
       - postgres_data:/var/lib/postgresql/data
     healthcheck: