Initial integration of light dark toggle using themeprovider

[mzkrasner]

• Integrates a light-dark toggle component into navigation (header)
• Integrates a theme provider to wrap the layout and provide theme state across child components
• Edits to destructive color to appear lighter when in dark mode
• Stores system preference in local storage

[kenny-io]

Thank you for this wonderful PR @mzkrasner

Just a little update needed. The NO_DATA status color is invisible across both dark and light mode.

At the moment, it looks like this (NO_DATA status color is invisible):

It should look like this:

To fix this, you could update the STATUS_COLORS in lib/constants to

  export const STATUS_COLORS = {
    [STATUS.NO_DATA]: 'bg-muted', 
    [STATUS.DOWN]: 'bg-red-500',
    [STATUS.UP]: 'bg-green-500',
    [STATUS.PARTIAL]: 'bg-orange-500',
  } as const;

The bg-muted class will automatically adapt to the theme since it's defined in the CSS variables.