style: replace upload-style share icon with two-person users icon across all views

frontend/src/features/settings/AdminSettingsView.tsx

@@ -13,7 +13,6 @@ import {
   Send,
   AlertCircle,
   UserPlus,
-  Share2,
 } from 'lucide-react';
 import {
   SystemSettings,
@@ -690,7 +689,7 @@ export const AdminSettingsView: React.FC<AdminSettingsViewProps> = ({
                 {/* Sharing Isolation Cards */}
                 <div className="space-y-2">
                   <label className="block text-muted font-semibold flex items-center gap-1.5">
-                    <Share2 className="w-4 h-4 text-accent" />
+                    <Users className="w-4 h-4 text-accent" />
                     <span>Globale Sharing- & Sichtbarkeits-Isolation</span>
                   </label>