feat: Set up initial monorepo structure for admin and mobile applications with core configurations and database integration.

innungsapp/apps/admin/app/dashboard/termine/neu/page.tsx

@@ -3,6 +3,7 @@
 import { useState } from 'react'
 import { useRouter } from 'next/navigation'
 import { trpc } from '@/lib/trpc-client'
+import { getTrpcErrorMessage } from '@/lib/trpc-error'
 import Link from 'next/link'
 
 const TYPEN = [
@@ -122,7 +123,7 @@ export default function TerminNeuPage() {
 
         {createMutation.error && (
           <p className="text-sm text-red-600 bg-red-50 px-4 py-2 rounded-lg">
-            {createMutation.error.message}
+            {getTrpcErrorMessage(createMutation.error)}
           </p>
         )}