chore: remove reference folders (CLI generates these) (#130)

Remove folders that were only used as reference/examples:
- .cursor/, .windsurf/, .kiro/, .roo/, .github/
- .agent/, .opencode/

These folders are no longer needed since CLI generates
all necessary files for users via `uipro init`.

Update CLAUDE.md architecture section accordingly.

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: viettranx