Dark Mode Theme Based on CSS Media Queries

[bliles]

Describe the feature:
Kibana now supports per-user settings for dark-mode, but it requires the user to select if they prefer light or dark mode. Instead of requiring the user to switch a setting, detect the user's preference using media queries and automatically use the correct mode for the user.

Describe a specific use case for the feature:
Some users switch between light and dark mode on different devices or at different times of day/lighting conditions. Using media queries means the user only needs to adjust the operating system setting instead of needing to change the mode preference in individual apps and sites.

[elasticmachine]

Pinging @elastic/kibana-security (Team:Security)

[legrego]

Thanks for raising this, @bliles. I'm going to close this as a duplicate of #89340, so that we can consolidate the discussion to a single issue.