docs: reorganize project documentation (#15)

## Summary
- add a root README with project overview, setup, usage, architecture, security, and contribution guidance
- replace stale planning and requirement notes with current 1.0 project overview
- update architecture and hardware validation docs to match the implemented app
- remove obsolete UI branch notes and the old Java/XML AsyncTask example
- remove the superpowers documentation and move vendor ABSDK references into docs/vendor
- preserve vendor Markdown and XLS content byte-for-byte

## Verification
- Markdown relative links checked
- vendor files verified as 100% Git renames
- git diff --check passed
- no application tests run; documentation-only change

Reviewed-on: #15
Co-authored-by: KremeCN <3265494849@qq.com>

docs/protocol/absdk-0630.md

@@ -7,7 +7,7 @@
 证据来源：
 
 - JAR：`samples/abox-sdk-sample/login-mac/libs/libABSDK0630.jar`；
-- 厂商文档：`docs/ABSDK接口部分_0630.md`；
+- 厂商文档：`docs/vendor/ABSDK接口部分_0630.md`；
 - 历史 Sample：`samples/abox-sdk-sample/login-mac/`；
 - 公开 API 使用 `javap` 验证，协议细节通过授权字节码分析验证。