fix: 外部审查 8 项修复 + 国密 TLS 按需回退

- UserAgent 默认值回退 + 注册 -ua flag (#2)
- README 编译命令 main.go → . (#3)
- README 版本号同步 rc.1 (#4)
- Client.go gmtls stdout 劫持删除 (#5)
- ms17010 smb1GetResponse size<32 越界 panic (#6)
- SSH 拨号超时统一 ModuleTimeout (#8)
- AddPorts 死字段删除 (#9)
- 国密 TLS 按需回退：标准 TLS 握手失败时仅在错误为
  cipher/protocol 不兼容时尝试国密，跳过超时/拒绝等连接级错误

common/i18n/locales/en.yaml

@@ -64,6 +64,8 @@ flag_urls_file:
   other: "URLs file"
 flag_cookie:
   other: "HTTP Cookie"
+flag_user_agent:
+  other: "Custom User-Agent header"
 flag_web_timeout:
   other: "Web timeout"
 flag_max_redirects:

common/i18n/locales/zh.yaml

@@ -64,6 +64,8 @@ flag_urls_file:
   other: "URL文件"
 flag_cookie:
   other: "HTTP Cookie"
+flag_user_agent:
+  other: "自定义 User-Agent 请求头"
 flag_web_timeout:
   other: "Web超时时间"
 flag_max_redirects: