feat: sing-box 下载默认经 https://git.86482425.xyz 代理

- GITHUB_PROXY 可配置；失败自动回退直连 GitHub

cpxy

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+set -euo pipefail
+ROOT="$(cd "$(dirname "$0")" && pwd)"
+cmd="${1:-help}"
+shift || true
+case "$cmd" in
+  detect)   exec "$ROOT/scripts/detect.sh" "$@" ;;
+  generate) exec "$ROOT/scripts/generate.sh" "$@" ;;
+  install)  exec "$ROOT/scripts/install.sh" "$@" ;;
+  verify)   exec "$ROOT/scripts/verify.sh" "$@" ;;
+  fetch)    exec "$ROOT/scripts/fetch-binaries.sh" "$@" ;;
+  help|*)
+    cat <<H
+./cpxy <cmd>
+  detect | generate | install | verify | fetch
+
+语义: 走本代理的连接一律从数据网卡出口（系统默认仍可走 WiFi）
+H
+    ;;
+esac