chore: deployment debugging - output standalone and global error boundary

.next/server/server-reference-manifest.js

@@ -1 +1 @@
-self.__RSC_SERVER_MANIFEST="{\n  \"node\": {},\n  \"edge\": {},\n  \"encryptionKey\": \"VlJgjz0/FjDMFtnwSM+tocLhNpsMtoMH2qjhwNqZlS8=\"\n}"
+self.__RSC_SERVER_MANIFEST="{\n  \"node\": {},\n  \"edge\": {},\n  \"encryptionKey\": \"l/OPnKIRnN1BmFcrFRSIU/W1xSwGbL96ruq9ikQxP4c=\"\n}"

.next/server/server-reference-manifest.json

@@ -1,5 +1,5 @@
 {
   "node": {},
   "edge": {},
-  "encryptionKey": "VlJgjz0/FjDMFtnwSM+tocLhNpsMtoMH2qjhwNqZlS8="
+  "encryptionKey": "l/OPnKIRnN1BmFcrFRSIU/W1xSwGbL96ruq9ikQxP4c="
 }

next.config.mjs

@@ -1,9 +1,9 @@
 /** @type {import('next').Config} */
 const nextConfig = {
+    output: 'standalone',
     productionBrowserSourceMaps: false,
+    transpilePackages: ['@supabase/auth-helpers-nextjs'],
     webpack: (config, { isServer, dev }) => {
-        // Disable source maps for the server build in production 
-        // to prevent EvalError in strict environments (e.g. Coolify)
         if (isServer && !dev) {
             config.devtool = false;
         }

src/app/error.tsx

@@ -0,0 +1,48 @@
+'use client';
+
+import { useEffect } from 'react';
+import { AlertTriangle, RefreshCcw } from 'lucide-react';
+
+export default function Error({
+    error,
+    reset,
+}: {
+    error: Error & { digest?: string };
+    reset: () => void;
+}) {
+    useEffect(() => {
+        console.error('App Crash Error:', error);
+    }, [error]);
+
+    return (
+        <div className="flex min-h-screen flex-col items-center justify-center p-6 bg-zinc-50 dark:bg-black text-center">
+            <div className="bg-white dark:bg-zinc-900 p-8 rounded-3xl border border-zinc-200 dark:border-zinc-800 shadow-xl max-w-md w-full space-y-6">
+                <div className="w-16 h-16 bg-red-100 dark:bg-red-900/30 text-red-600 dark:text-red-400 rounded-2xl flex items-center justify-center mx-auto">
+                    <AlertTriangle size={32} />
+                </div>
+
+                <div className="space-y-2">
+                    <h2 className="text-2xl font-black text-zinc-900 dark:text-white">Hoppla! Ein Fehler.</h2>
+                    <p className="text-zinc-500 text-sm">
+                        Die App ist auf ein Problem gestoßen. Das kann an fehlenden Umgebungsvariablen oder Verbindungsproblemen liegen.
+                    </p>
+                </div>
+
+                {error.message && (
+                    <div className="p-4 bg-zinc-100 dark:bg-zinc-800 rounded-xl text-left">
+                        <p className="text-[10px] font-black uppercase text-zinc-400 mb-1 tracking-widest">Fehlermeldung:</p>
+                        <p className="text-xs font-mono text-zinc-600 dark:text-zinc-300 break-all">{error.message}</p>
+                    </div>
+                )}
+
+                <button
+                    onClick={() => reset()}
+                    className="w-full py-4 bg-amber-600 hover:bg-amber-700 text-white rounded-xl font-bold flex items-center justify-center gap-2 transition-all"
+                >
+                    <RefreshCcw size={18} />
+                    Erneut versuchen
+                </button>
+            </div>
+        </div>
+    );
+}