Bug: after "Clear all" + "Apply", the builder's photo (or art_style) field
stayed filled. applyToBuilder computed kind=null when both were empty and
skipped the style block entirely, leaving the builder's previous value.
Fix: mirror the wizard exactly — when both are empty, set the builder's
"style" combo to "none" (its DynamicCombo drops the photo/art_style
sub-widget, actually clearing it), matching how the builder's own
applyCaption handles a style-less import.
Also add a "Clear & apply" button (clears the wizard and pushes the cleared
state to the builder in one click).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
