[Bug]: Light / Dark theme does not auto-update without a page refresh

[acerspyro]

What happened?

When the theme is set to "System", it doesn't automatically update when the system theme changes from light to dark, and vice versa, until the user refreshes.

The media query value for the preferred theme should be watched to update on the fly.

Steps to Reproduce

1. Open LibreChat
2. Set the theme to "System"
3. Change the system theme

What browsers are you seeing the problem on?

No response

Relevant log output

No response

Screenshots

No response

Code of Conduct

• I agree to follow this project's Code of Conduct

[acerspyro]

You are machines, @berry-13, @danny-avila, thank you!

I can confirm that the fix works.