feat: Allow event owners to delete their own events and admins to delete any event with UI action buttons and confirmation dialog

frontend/src/components/ShiftMatrixTable.jsx

@@ -1,7 +1,7 @@
 /* Hallmark · pre-emit critique: P5 H5 E5 S5 R5 V5 */
 /* Hallmark · component: shift-matrix-table · genre: editorial · theme: Atelier (Dark & Light) · studied-DNA: https://inihaus.de */
 import React from 'react';
-import { Clock, UserCheck, Shield, Printer, Download, Award, CheckCircle2, UserX, UserPlus, MapPin, Edit3 } from 'lucide-react';
+import { Clock, UserCheck, Shield, Printer, Download, Award, CheckCircle2, UserX, UserPlus, MapPin, Edit3, Trash2 } from 'lucide-react';
 
 export default function ShiftMatrixTable({
   event,
@@ -12,7 +12,8 @@ export default function ShiftMatrixTable({
   onGenerateClaimLink,
   onExportPdf,
   onPrintView,
-  onEditEvent
+  onEditEvent,
+  onDeleteEvent
 }) {
   if (!event || !event.task_areas || event.task_areas.length === 0) {
     return (
@@ -71,6 +72,15 @@ export default function ShiftMatrixTable({
               <Edit3 className="w-3.5 h-3.5" /> SCHICHTEN BEARBEITEN
             </button>
           )}
+          {user && (user.is_admin_user || user.is_staff || user.is_superuser || event?.created_by === user.id || event?.created_by?.id === user.id) && onDeleteEvent && (
+            <button
+              onClick={() => onDeleteEvent(event)}
+              className="px-3.5 py-1.5 rounded-sm bg-red-500/10 hover:bg-red-500/20 text-red-400 border border-red-500/30 transition flex items-center gap-1.5 font-bold"
+              title="Diese Veranstaltung unwiderruflich löschen"
+            >
+              <Trash2 className="w-3.5 h-3.5" /> LÖSCHEN
+            </button>
+          )}
           <button
             onClick={onPrintView}
             className="px-3.5 py-1.5 rounded-sm bg-surface hover:bg-surface-hover text-main border border-grid transition flex items-center gap-1.5 font-bold"