JSONForm - Generate Form button apply theme on new fields

Editor assessment

The subject describes the fix concretely: the Generate Form button in JSONForm now applies the theme to newly added fields. The trigger, the component, and the effect are all identifiable without the diff. The fix type matches a styling-propagation correction. No body explains how new fields escaped theming — presumably missing style bindings — which is the mechanism a body would teach, but the essential behavior is communicated and the change is contained. Style is clean: no trailing period, no junk, no footers needed. Good and publishable.