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

frontend/src/features/auth/SetupAndAuthView.tsx

@@ -7,7 +7,7 @@ import {
   UserPlus,
   LogIn,
   Server,
-  Share2,
+  Users,
   Check,
   AlertCircle,
 } from 'lucide-react';
@@ -235,7 +235,7 @@ export const SetupAndAuthView: React.FC<SetupAndAuthViewProps> = ({
 
               <div>
                 <label className="block text-muted mb-1.5 flex items-center gap-1">
-                  <Share2 className="w-3 h-3 text-accent" />
+                  <Users className="w-3 h-3 text-accent" />
                   <span>Sichtbarkeit & Sharing-Isolation zwischen Benutzern</span>
                 </label>
                 <div className="grid grid-cols-1 sm:grid-cols-3 gap-2">