optimize: docker up 自动清理历史 build cache，新增 docker clean 子命令

run.sh

@@ -319,6 +319,13 @@ cmd_docker() {
             banner "========== Docker Compose 启动 =========="
             $DOCKER_COMPOSE up -d --build
             echo ""
+            # 清理历史 build cache，防止占满磁盘
+            info "清理历史构建缓存..."
+            local before_prune=$(df -h / | awk 'NR==2{print $5}')
+            docker builder prune -f 2>/dev/null || true
+            local after_prune=$(df -h / | awk 'NR==2{print $5}')
+            info "磁盘使用: ${before_prune} → ${after_prune}"
+            echo ""
             info "等待服务就绪..."
             sleep 5
             $DOCKER_COMPOSE ps
@@ -349,6 +356,22 @@ cmd_docker() {
         ps|status)
             $DOCKER_COMPOSE ps
             ;;
+        clean|prune)
+            banner "========== Docker 缓存清理 =========="
+            info "清理前磁盘使用:"
+            echo "  $(df -h / | awk 'NR==2{print $3, "used /", $2, "total ("$5")"}')"
+            echo ""
+            info "清理 dangling 镜像..."
+            docker image prune -f 2>/dev/null || true
+            info "清理构建缓存..."
+            docker builder prune -f 2>/dev/null || true
+            info "清理未使用的网络..."
+            docker network prune -f 2>/dev/null || true
+            echo ""
+            info "清理后磁盘使用:"
+            echo "  $(df -h / | awk 'NR==2{print $3, "used /", $2, "total ("$5")"}')"
+            success "清理完成"
+            ;;
         help|--help|-h)
             echo "Docker Compose 部署命令:"
             echo "  ./run.sh docker up        构建并启动所有容器"
@@ -357,6 +380,7 @@ cmd_docker() {
             echo "  ./run.sh docker restart   重启容器"
             echo "  ./run.sh docker logs      查看实时日志"
             echo "  ./run.sh docker ps        查看容器状态"
+            echo "  ./run.sh docker clean     清理构建缓存/无用镜像"
             ;;
         *)
             error "未知 docker 子命令: $action"