Migrate to Vite

[v1lling]

Related to Issue #303

The build system was migrated from react-scripts to Vite in order to resolve security vulnerabilities and improve build performance.

• All npm vulnerabilities were eliminated.
• Build times and hot reload are significantly faster.
• Modern, actively maintained tooling.
• Reduced bundle size.

Breaking changes:
The Config.js format: JavaScript configuration files must now use [...]
window.config = {... ';
instead of
export default {...} }

The location remains the same (/public/config.js).
JSON configuration files (config.json) remain unaffected.
The README has been updated with migration instructions.

@dsternlicht
It works in my environment and my RESTool setup (config.js), but users who have made custom modifications may encounter additional issues. This is a suggestion for the project. Whether to merge this migration or handle it differently is up to you.

[v1lling]

Hi @dsternlicht 👋
Quick check-in on this one - anything I can do to help get it merged? If the breaking changes are a concern and you'd rather not include it, totally fine too - just good to know either way.