Replace rm -rf in vite-plugin build with a cross-platform dist cleanup

[rioredwards]

The published Vite plugin package uses a POSIX-only cleanup step in its build script. That breaks Windows builds for contributors and anyone building the package from source.

Problem

• packages/vite-plugin-component-preview/package.json uses rm -rf dist in the build script
• this works on macOS and Linux shells but fails in standard Windows environments

Suggested fix

• Replace the cleanup step with a cross-platform approach such as fs.rm, rimraf, or a small Node script
• Keep the existing build behavior unchanged apart from platform compatibility
• Add a quick CI or script-level check if you want to prevent regressions

Relevant files

• packages/vite-plugin-component-preview/package.json