feat: select text across bullets and delete it like a text editor; Ctrl+Z in tasks; notes and lists without emoji; custom done columns complete tasks

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

frontend/src/features/workspace/TrashView.tsx

@@ -88,7 +88,7 @@ export const TrashView: React.FC<TrashViewProps> = ({ items, onOpen, onRestore,
                   className="flex items-center gap-2.5 flex-1 min-w-0 text-left cursor-pointer group"
                   title="Schreibgeschützt ansehen"
                 >
-                  <span className="text-lg shrink-0">{t.icon || '🗒️'}</span>
+                  {t.icon && <span className="text-lg shrink-0">{t.icon}</span>}
                   <span className="min-w-0">
                     <span className="block text-sm font-semibold text-main truncate group-hover:text-accent">
                       {t.title || 'Unbenannte Notiz'}