Add rotating gradient border on running LED target cards

Animated conic gradient spins around the card edge using CSS Houdini
@property for smooth angle interpolation. Skips the left edge when
a custom card color stripe is assigned (data-has-color attribute).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/wled_controller/static/js/features/targets.js

@@ -978,6 +978,7 @@ export function createTargetCard(target, deviceMap, colorStripSourceMap, valueSo
     return wrapCard({
         dataAttr: 'data-target-id',
         id: target.id,
+        classes: isProcessing ? 'card-running' : '',
         removeOnclick: `deleteTarget('${target.id}')`,
         removeTitle: t('common.delete'),
         content: `