* fix(install): implement safety backup during migration to prevent data loss
* fix: safely migrate skills by backing up directory and preserving permissions
- The installer uses copyRecursiveSync which copies files,
not symlinks, so git clone without core.symlinks works fine
- The previous Windows-specific git -c core.symlinks=true clone
required admin privileges, causing install failures
- This fix allows non-admin Windows users to install
Fixes#286
Co-authored-by: 阳虎 <yanghu@yanghudeMacBook-Pro.local>
Consolidate the repository into clearer apps, tools, and layered docs areas so contributors can navigate and maintain it more reliably. Align validation, metadata sync, and CI around the same canonical workflow to reduce drift across local checks and GitHub Actions.
