fix: replace Bun-specific APIs with Node.js APIs for npm compatibility

- Replace Bun.spawn with exec from child_process in extract.ts
- Replace Bun.file().exists() with access from fs/promises
- Replace Bun.write with writeFile from fs/promises in github.ts
- Add cp and rm from fs/promises for file operations
- Bump version to 1.0.2

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

cli/package.json

@@ -1,6 +1,6 @@
 {
   "name": "uipro-cli",
-  "version": "1.0.0",
+  "version": "1.0.2",
   "description": "CLI to install UI/UX Pro Max skill for AI coding assistants",
   "type": "module",
   "bin": {