fix: resolve dropdown menu visibility issue in admin events table

- Changed Card container from overflow-hidden to overflow-visible
- Added overflow-y-visible to prevent vertical clipping
- Dropdown menu now properly displays even with few events
- Table only scrolls when content exceeds viewport height

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

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

frontend/src/pages/admin/EventsListPage.tsx

@@ -272,8 +272,8 @@ export const EventsListPage: React.FC = () => {
       </Card>
 
       {/* Events Table */}
-      <Card className="overflow-hidden">
-        <div className="overflow-x-auto">
+      <Card className="overflow-visible">
+        <div className="overflow-x-auto overflow-y-visible">
           <table className="w-full">
             <thead className="bg-neutral-50 border-b border-neutral-200">
               <tr>