docs(readme): star-history chart + ci(sync-about): sync docs config count (#188)

Add a dark-mode star-history chart under the README footer thank-you line (all existing badges kept), and make sync-about also patch the indicator count into wickra-docs .vitepress/config.ts.

.github/workflows/sync-about.yml

@@ -180,14 +180,14 @@ jobs:
             exit 0
           fi
           cd docs-count
-          sed -i -E "s/[0-9]+ (streaming-first )?indicators/${n} \1indicators/g" index.md overview.md Indicators-Overview.md
+          sed -i -E "s/[0-9]+ (streaming-first )?indicators/${n} \1indicators/g" index.md overview.md Indicators-Overview.md .vitepress/config.ts
           if git diff --quiet; then
             echo "Docs indicator count unchanged."
             exit 0
           fi
           git config user.name "wickra-bot"
           git config user.email "wickra-bot@users.noreply.github.com"
-          git add index.md overview.md Indicators-Overview.md
+          git add index.md overview.md Indicators-Overview.md .vitepress/config.ts
           git commit -m "chore: sync indicator count to ${n}"
           if ! git push 2>/dev/null; then
             echo "::warning::push to wickra-lib/wickra-docs failed — ABOUT_SYNC_TOKEN likely lacks write (findings P10.0a)."

README.md

@@ -428,8 +428,8 @@ The library is provided **as is**, without warranty of any kind; see
 </p>
 
 <p align="center">
-  <a href="https://github.com/wickra-lib/wickra">
-    <img alt="Star Wickra on GitHub"
-         src="https://img.shields.io/badge/%E2%AD%90%20Star%20Wickra%20on%20GitHub-1f2328?style=for-the-badge&logo=github&logoColor=ffd866&labelColor=1f2328">
+  <a href="https://star-history.com/#wickra-lib/wickra&Date">
+    <img alt="Wickra star history" width="640"
+         src="https://api.star-history.com/svg?repos=wickra-lib/wickra&type=Date&theme=dark">
   </a>
 </p>