docs: add DESIGN.md, the portable bash + skills design

README.md

@@ -10,7 +10,7 @@ Hire Google's Antigravity CLI (`agy`) as a staffer for **Claude Code**, **OpenAI
 
 ![agy-staff design](assets/design.png)
 
-**[Install](#install) · [Examples](#cujs) · [Core design](#core-design) · [Upgrade](#upgrade)**
+**[Install](#install) · [Examples](#cujs) · [Core design](#core-design) · [Build your own](#build-one-for-another-cli) · [Upgrade](#upgrade)**
 
 ## What & Why
 
@@ -145,6 +145,20 @@ Jobs have a separate execution deadline: default 60 minutes, configurable at lau
 
 **Full reference →** [docs/REFERENCE.md](docs/REFERENCE.md) (flags, permission model, jobs/state, troubleshooting, upgrading). **Release notes →** [docs/releases/](docs/releases/).
 
+## Build one for another CLI
+
+agy-staff's design is portable: bash plus skills, with no hard dependency on a host, a worker CLI or a runtime library. [docs/DESIGN.md](docs/DESIGN.md) writes it down as best practice. To build the same kind of tool for another agent CLI, give your coding agent this prompt:
+
+```
+Read the raw text of https://raw.githubusercontent.com/keli-wen/agy-staff/master/docs/DESIGN.md
+(curl it — do not work from a summary). Then design an integration that lets this host agent delegate
+work to <CLI> the same way. First read `<CLI> --help`, map what the CLI supports to the section
+"What depends on the worker CLI", and list the principles it cannot support before writing any code.
+Ask me before any call that spends model quota. Respond in the user's language.
+```
+
+Before writing any code, the agent lists the principles your CLI cannot support, so you know up front where the tool will degrade.
+
 ## Community
 
 - [LINUX DO](https://linux.do/) — A next-generation Linux community.

README.zh-CN.md

@@ -10,7 +10,7 @@
 
 ![agy-staff 设计图](assets/design.png)
 
-**[安装](#安装) · [使用示例](#使用) · [核心设计](#核心设计) · [升级](#升级)**
+**[安装](#安装) · [使用示例](#使用) · [核心设计](#核心设计) · [为其他 CLI 做一个](#为其他-cli-做一个) · [升级](#升级)**
 
 ## 它适合做什么
 
@@ -130,6 +130,20 @@ install and verify the agy-staff plugin for the harness you are running in. Resp
 
 关于参数、权限、进度快照和恢复方式，可以查阅[完整参考手册](docs/REFERENCE.zh-CN.md)。各版本的改动记录在[发布说明](docs/releases/)中。
 
+## 为其他 CLI 做一个
+
+agy-staff 的设计是可移植（portable）的：只用 bash 和 skills，不强依赖特定的宿主、worker CLI 或运行时库。[docs/DESIGN.md](docs/DESIGN.md)（英文）把这套设计整理成了最佳实践。如果想为其他 agent CLI 做同类工具，可以把下面这段话交给你的 coding agent：
+
+```
+Read the raw text of https://raw.githubusercontent.com/keli-wen/agy-staff/master/docs/DESIGN.md
+(curl it — do not work from a summary). Then design an integration that lets this host agent delegate
+work to <CLI> the same way. First read `<CLI> --help`, map what the CLI supports to the section
+"What depends on the worker CLI", and list the principles it cannot support before writing any code.
+Ask me before any call that spends model quota. Respond in the user's language.
+```
+
+agent 动手写代码之前，会先列出你的 CLI 支持不了哪些原则，让你提前知道工具会在哪些地方降级。
+
 ## 升级
 
 Claude Code 和 Codex 使用的是安装时复制到缓存中的插件。仓库发布新版本后，需要主动更新，并重启应用才能加载新的技能。