docs: rebrand README for DeepSeek Harness SDK

Replace outdated references to 'DeepSeek Code' with the correct
product name 'DeepSeek Harness SDK'. Update demo commands to
reflect the SDK nature (demo:agent, demo:acp) rather than the
old coding-agent product.

README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write
-README.md: 33c03fad1450d91ba1adef3d89ce44d0ff73c25b
-README.zh.md: 9d520023c528810ce75ee80efec2f2f087fb7b0e
+README.md: 175ab76ebb1cd4f635bced46c6edd448b9fb4d45
+README.zh.md: af7a6baf10b9588ff67ab967b5829ecee551533b

README.md

@@ -2,11 +2,7 @@
 
 English | [中文](README.zh.md)
 
-Monorepo for the DeepSeek Harness group.
-
-## Projects
-
-- **DeepSeek Code** — DeepSeek's coding agent product.
+The **DeepSeek Harness SDK** is a plugin-based SDK for building agent harnesses.
 
 ## Development
 
@@ -16,7 +12,7 @@ This monorepo is built on the [Cordis](https://github.com/cordiverse/cordis) fra
 pnpm install
 pnpm run test          # vitest
 pnpm run demo:echo     # runnable echo-agent example (no API key needed)
-pnpm run demo:coding   # the real DeepSeek coding agent (needs DEEPSEEK_API_KEY)
+pnpm run demo:coding   # full-featured agent harness demo (needs DEEPSEEK_API_KEY)
 ```
 
 For humans, start with the [development guide](docs/development.md) for local setup, hooks, environment variables, and quality gates, then read the [architecture design](docs/architecture.md) before package work. Local context lives in [packages/](packages/) and [vendor/](vendor/).

README.zh.md

@@ -2,11 +2,7 @@
 
 [English](README.md) | 中文
 
-DeepSeek Harness 小组的 monorepo。
-
-## 项目
-
-- **DeepSeek Code** — DeepSeek 的编码 agent（智能体）产品。
+**DeepSeek Harness SDK** 是一个基于插件的 SDK，用于构建 agent harness。
 
 ## 开发
 
@@ -16,7 +12,7 @@ DeepSeek Harness 小组的 monorepo。
 pnpm install
 pnpm run test          # vitest
 pnpm run demo:echo     # runnable echo-agent example (no API key needed)
-pnpm run demo:coding   # the real DeepSeek coding agent (needs DEEPSEEK_API_KEY)
+pnpm run demo:coding   # full-featured agent harness demo (needs DEEPSEEK_API_KEY)
 ```
 
 面向人类读者：先读[开发指南](docs/development.md)了解本地环境搭建、钩子、环境变量与质量门禁，动手改 package 之前再读[架构设计](docs/architecture.md)。局部上下文见 [packages/](packages/) 与 [vendor/](vendor/)。