Revert "Remove cx from ThemeSettings (#38836)" (#39691)

This reverts commit a2a7bd139a3f94202d2a050a2bc7e50dc139000b.

This caused themes to not load correctly on startup, you needed to edit
your settings.

Release Notes:

- N/A
41cf114d8aConrad Irwin committed on 10/7/2025, 3:45:20 PM· committed by GitHubparente765818
60 files changedLine totals unavailable