Fix Docker build without VPN proxy dependency

Make build proxy optional and use Arvan mirrors for apt/pip by default. Fixes 503 errors when xray proxy on 172.17.0.1:1081 is unavailable during Dokploy deploy.

Co-authored-by: Cursor <cursoragent@cursor.com>

docker-compose.yml

@@ -3,11 +3,12 @@ services:
     build:
       context: .
       dockerfile: Dockerfile
-      network: host
       args:
         BASE_IMAGE: docker.arvancloud.ir/library/python:3.12-slim-bookworm
-        HTTP_PROXY: http://172.17.0.1:1081
-        HTTPS_PROXY: http://172.17.0.1:1081
+        PYPI_INDEX: https://mirror.arvancloud.ir/pypi/simple
+        # اختیاری — فقط اگر xray روی host فعال است:
+        BUILD_HTTP_PROXY: ${BUILD_HTTP_PROXY:-}
+        BUILD_HTTPS_PROXY: ${BUILD_HTTPS_PROXY:-}
     container_name: mirror-manager
     restart: unless-stopped
     privileged: true