Add loading.js and error.js for all routes, secure admin page with 404

- Added loading.js (dark/light variants) for all 14 routes
- Added error.js (dark/light variants) for all 14 routes
- Added global not-found.js and loading.js at root
- Admin page shows 404 illustration for non-admin users instead of redirecting

app/register/tenant/error.js

@@ -0,0 +1,27 @@
+'use client';
+
+import { motion } from 'framer-motion';
+import { AlertTriangle, RefreshCw, Home } from 'lucide-react';
+import Link from 'next/link';
+
+export default function Error({ error, reset }) {
+  return (
+    <div className="min-h-screen bg-gradient-to-br from-gray-950 via-gray-900 to-gray-950 flex items-center justify-center p-4">
+      <motion.div initial={{ opacity: 0, y: 20 }} animate={{ opacity: 1, y: 0 }} className="text-center max-w-md">
+        <div className="w-20 h-20 bg-red-500/20 rounded-full flex items-center justify-center mx-auto mb-6">
+          <AlertTriangle className="w-10 h-10 text-red-500" />
+        </div>
+        <h2 className="text-2xl font-bold text-white mb-2">حدث خطأ</h2>
+        <p className="text-gray-400 mb-8">نعتذر، حدث خطأ أثناء تحميل الصفحة</p>
+        <div className="flex gap-3 justify-center">
+          <button onClick={reset} className="flex items-center gap-2 bg-amber-500 text-white px-6 py-3 rounded-xl font-medium hover:bg-amber-600 transition-colors">
+            <RefreshCw className="w-5 h-5" /> إعادة المحاولة
+          </button>
+          <Link href="/" className="flex items-center gap-2 bg-white/10 text-gray-300 px-6 py-3 rounded-xl font-medium hover:bg-white/20 transition-colors">
+            <Home className="w-5 h-5" /> الرئيسية
+          </Link>
+        </div>
+      </motion.div>
+    </div>
+  );
+}

app/register/tenant/loading.js

@@ -0,0 +1,14 @@
+'use client';
+
+import { motion } from 'framer-motion';
+
+export default function Loading() {
+  return (
+    <div className="min-h-screen bg-gradient-to-br from-gray-950 via-gray-900 to-gray-950 flex items-center justify-center">
+      <motion.div initial={{ opacity: 0 }} animate={{ opacity: 1 }} className="text-center">
+        <div className="w-14 h-14 border-4 border-amber-500 border-t-transparent rounded-full animate-spin mx-auto mb-4" />
+        <p className="text-gray-400 text-lg">جاري التحميل...</p>
+      </motion.div>
+    </div>
+  );
+}