chore(release): .env.deploy 配 BUILD_PROXY 时构建镜像自动经代理

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01Cxwgnn2pbzQ7rXv3rq7fei

docker/compose.env.example

@@ -83,3 +83,6 @@ CAMOFOX_ACCESS_KEY=
 # [email protected]
 # TLS_PORT=443
 # TLS_BIND=0.0.0.0
+
+# 构建镜像时的出站代理(可选;直连下载 Deno 运行时可能卡住时填,如经宿主中继 http://172.17.0.1:7891)
+BUILD_PROXY=