docs: add Star History chart to READMEs

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

README.md

@@ -178,3 +178,7 @@ MIT
 ## Acknowledgments
 
 Inspired by [OpenClaw](https://github.com/openclaw/openclaw) and [Nanobot](https://github.com/HKUDS/nanobot). MimiClaw reimplements the core AI agent architecture for embedded hardware — no Linux, no server, just a $5 chip.
+
+## Star History
+
+[![Star History Chart](https://api.star-history.com/svg?repos=memovai/mimiclaw&type=Date)](https://star-history.com/#memovai/mimiclaw&Date)

README_CN.md

@@ -193,3 +193,7 @@ MIT
 ## 致谢
 
 灵感来自 [OpenClaw](https://github.com/openclaw/openclaw) 和 [Nanobot](https://github.com/HKUDS/nanobot)。MimiClaw 为嵌入式硬件重新实现了核心 AI Agent 架构 — 没有 Linux，没有服务器，只有一颗 $5 的芯片。
+
+## Star History
+
+[![Star History Chart](https://api.star-history.com/svg?repos=memovai/mimiclaw&type=Date)](https://star-history.com/#memovai/mimiclaw&Date)