Switch from Rolldown to esbuild, build to index.cjs

- Replace Rolldown with esbuild for more reliable bundling
- Configure esbuild to output CommonJS to index.cjs
- Update action.yml to use index.cjs as main entry point
- Remove problematic rolldown.config.js
- Bump version to 0.0.3
- ESM codebase with CJS build output for GitHub Actions compatibility

package.json

@@ -1,6 +1,6 @@
 {
   "name": "action",
-  "version": "0.0.2",
+  "version": "0.0.3",
   "main": "index.js",
   "directories": {
     "example": "examples"