修复service硬编码路径问题：动态替换部署路径，支持任意目录部署

autossl.service

@@ -6,11 +6,11 @@ Wants=network.target
 [Service]
 Type=simple
 User=root
-WorkingDirectory=/root/auto-ssl/backend
+WorkingDirectory={{DEPLOY_DIR}}/backend
 Environment="PORT=9090"
 Environment="ACME_PORT=8082"
 Environment="GIN_MODE=release"
-ExecStart=/root/auto-ssl/backend/autossl
+ExecStart={{DEPLOY_DIR}}/backend/autossl
 Restart=always
 RestartSec=3
 StandardOutput=journal+console