chore: change license to BSL-1.1 and remove third-party brand keywords (#605)

- Switch from MIT to Business Source License 1.1 (non-commercial use,
  auto-converts to Apache 2.0 on 2029-05-10)
- Remove third-party brand keywords from package.json (chatgpt, claude,
  openai, gemini, deepseek, telegram, discord, slack, whatsapp, etc.)
- Remove afdian sponsor links from README.md and README_zh.md
- Update license references in both READMEs to BSL-1.1

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

README.md

@@ -274,12 +274,6 @@ The BFF layer handles API proxy (with path rewriting), SSE streaming, file uploa
 
 <!-- If the chart above doesn't load, visit https://star-history.com/#EKKOLearnAI/hermes-web-ui -->
 
-## Sponsor
-
-如果你觉得这个项目对你有帮助，欢迎支持我：
-
-<a href="https://ifdian.net/a/ekko8888"><img src="https://img.shields.io/badge/Sponsor-%E7%88%B1%E5%8F%91%E7%94%B5-orange?style=flat-square" alt="Sponsor"/></a>
-
 ## License
 
-[MIT](./LICENSE)
+[BSL-1.1](./LICENSE)