fix(ui): Add top padding to sort tabs

Add spacing between header border and sort tabs for better visual
separation.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/modules/nostr-feed/components/SortTabs.vue

@@ -64,7 +64,7 @@ function selectTimeRange(range: TimeRange) {
 </script>
 
 <template>
-  <div class="flex items-center gap-1 text-sm border-b border-border pb-2 mb-2">
+  <div class="flex items-center gap-1 text-sm border-b border-border pt-3 pb-2 mb-2">
     <!-- Sort tabs -->
     <template v-for="option in sortOptions" :key="option.id">
       <button