chore(assets): remove HTML content and add debug styles

[keyserfaty]

Summary

This PR removes all HTML content from the main index file and adds temporary debug styling to assist with development. The changes appear to be part of a cleanup or refactoring effort, with the index.html being stripped down to an empty template and debug styles applied to the main layout container.

Changes

• Removed all content from public/index.html including meta tags, Google Analytics script, and Firebase initialization
• Changed background gradient in MainLayout to solid red color for debugging purposes
• Added newline at end of selectors.js file
• Added newline at end of vfs_fonts.js file

Testing

1. Run the application locally and verify it still starts without errors
2. Check that the main layout container now displays with a red background instead of the previous gradient
3. Verify that removing the HTML content doesn't break the application bootstrap process
4. Confirm that Firebase and Analytics are being initialized elsewhere in the application if still needed

Note: This appears to be a work-in-progress change with debug styling. The red background should likely be reverted before merging to production.