New features

• Add the ability to customize theme variants through config

• Added month/year controls beside Today across product forms, calendar popups, CBAT UI, and admin calendars.
• Calendar changes refresh automatically while preserving selected dates and times.
• Customer navigation respects booking windows, minimum notice, and variation overrides.
• Admin calendars support historical navigation; broad or unlimited windows allow year entry.
• Improved responsive toolbar layout with consistent control sizing, grouped arrows, and titles above the toolbar.

- Issue #3623290: Allow subtitles to be enabled by default.
- Issue #3627259: Show the Rijksvideo player on the media edit form.

Redisplay the banner when its content is edited.
Add an option to force the banner to be displayed again.
Option to reverse the condition for restricted pages.
Fix compatibility issues with Drupal 12