Use the admin theme variables of Default Admin, Gin and Claro in the stylesheet

Problem/Motivation

The module stylesheet reads Default Admin's variables, then Gin's, then falls back to hard-coded colors. Claro's variables are never read, so on Claro the switch and the generator form use the fallback values instead of the theme's own, and the radius, spacing and font sizes are fixed numbers in every theme.

Proposed resolution

• Resolve every value Default Admin, then Gin, then Claro, then a plain fallback that matches Claro's own value.
• Add the shared radius, spacing, font size and semibold weight variables to the chain.
• Style only the module's own classes; the rest of the form stays the theme's. The markup keeps the themes' common classes: button, button--small, form-item__description, visually-hidden, gin-new-flag and admin-new-flag.

Remaining tasks

• ✅ File an issue
• ✅ Addition/Change/Update/Fix
• ✅ Testing to ensure no regression
• ➖ Automated unit/functional testing coverage
• ➖ Developer Documentation support
• ➖ User Guide Documentation support
• ➖ UX/UI designer responsibilities
• ➖ Accessibility and Readability
• ❌ Reviewed by a human
• ❌ Code review by maintainers
• ❌ Full testing and approval
• ❌ Credit contributors
• ❌ Review with the product owner
• ✅ Update Release Notes
• ✅ Release

User interface changes

Before, on 1.0.x, and after, in Gin: the same values, now read from the theme. In Default Admin the two are identical as well.

Before:

After:

API changes

• N/A

Data model changes

• N/A

Release notes snippet

• The stylesheet reads the admin theme's variables: Default Admin, Gin and Claro.

AI-Generated: Yes