server_config: 重写为完整部署规范（BBR/nginx CONNECT/sing-box/mtg）

- 新增完整 README.md 部署规范：架构、端口规划、BBR 跨境优化、
  nginx 源码编译+CONNECT 隧道、sing-box(VLESS+REALITY/SS)、mtg(MTProto)、
  本机 IP 自动识别、systemd、启动顺序与验证清单
- nginx/nginx.conf：占位符版，proxy_connect_allow all + 回环保护
- sing-box/config.json：占位符版，VLESS+REALITY + SS
- systemd/：nginx/sing-box/mtg 服务文件
- scripts/sync-nginx-local-ips.sh：去除真实域名，占位符版
- fake-site/index.html：伪装页（清除真实品牌域名）
- 移除过时：traffic-monitor/、pac/、conf.d 具体站点配置
- 所有敏感值（IP/域名/端口/密钥）均以 <占位符> 表示

server_config/systemd/mtg.service

@@ -0,0 +1,12 @@
+[Unit]
+Description=MTProto proxy (mtg) for Telegram
+After=network.target
+
+[Service]
+Type=simple
+ExecStart=/usr/local/bin/mtg simple-run --prefer-ip=prefer-ipv4 0.0.0.0:<mtproto端口> <MTPROTO_SECRET>
+Restart=on-failure
+RestartSec=5
+
+[Install]
+WantedBy=multi-user.target

server_config/systemd/nginx.service

@@ -0,0 +1,16 @@
+[Unit]
+Description=nginx (RRPP proxy, compiled with ngx_http_proxy_connect_module)
+After=network.target
+
+[Service]
+Type=forking
+PIDFile=/var/run/nginx.pid
+ExecStartPre=/usr/local/nginx/sbin/nginx -t
+ExecStart=/usr/local/nginx/sbin/nginx
+ExecReload=/usr/local/nginx/sbin/nginx -s reload
+ExecStop=/usr/local/nginx/sbin/nginx -s quit
+Restart=on-failure
+RestartSec=5
+
+[Install]
+WantedBy=multi-user.target

server_config/systemd/sing-box.service

@@ -0,0 +1,12 @@
+[Unit]
+Description=sing-box (VLESS+REALITY / Shadowsocks)
+After=network.target
+
+[Service]
+Type=simple
+ExecStart=/usr/local/bin/sing-box -D /var/lib/sing-box -C /etc/sing-box run
+Restart=on-failure
+RestartSec=5
+
+[Install]
+WantedBy=multi-user.target