feat: upgrade next-auth to v5.0.0-beta.29 and refactor authentication middleware

- Updated next-auth dependency in package.json to version 5.0.0-beta.29.
- Refactored create-admin script to use a valid email format.
- Implemented authentication middleware for various API routes to enforce access control.
- Refactored API route handlers to improve readability and maintainability.
- Enhanced error handling in authentication error page.
- Added detailed tests for authentication flow, including protected routes and NextAuth endpoints.

test-nextauth.mjs

@@ -0,0 +1,47 @@
+// Simple test for NextAuth endpoints
+const BASE_URL = 'http://localhost:3000';
+
+async function testNextAuthEndpoints() {
+  console.log('🔐 Testing NextAuth Endpoints\n');
+  
+  // Test session endpoint
+  try {
+    const sessionResponse = await fetch(`${BASE_URL}/api/auth/session`);
+    console.log(`Session endpoint: ${sessionResponse.status} ${sessionResponse.statusText}`);
+    
+    if (sessionResponse.ok) {
+      const sessionData = await sessionResponse.json();
+      console.log(`Session data: ${JSON.stringify(sessionData)}\n`);
+    }
+  } catch (error) {
+    console.log(`Session endpoint error: ${error.message}\n`);
+  }
+  
+  // Test providers endpoint
+  try {
+    const providersResponse = await fetch(`${BASE_URL}/api/auth/providers`);
+    console.log(`Providers endpoint: ${providersResponse.status} ${providersResponse.statusText}`);
+    
+    if (providersResponse.ok) {
+      const providersData = await providersResponse.json();
+      console.log(`Providers: ${JSON.stringify(providersData, null, 2)}\n`);
+    }
+  } catch (error) {
+    console.log(`Providers endpoint error: ${error.message}\n`);
+  }
+  
+  // Test CSRF endpoint
+  try {
+    const csrfResponse = await fetch(`${BASE_URL}/api/auth/csrf`);
+    console.log(`CSRF endpoint: ${csrfResponse.status} ${csrfResponse.statusText}`);
+    
+    if (csrfResponse.ok) {
+      const csrfData = await csrfResponse.json();
+      console.log(`CSRF token present: ${csrfData.csrfToken ? 'Yes' : 'No'}\n`);
+    }
+  } catch (error) {
+    console.log(`CSRF endpoint error: ${error.message}\n`);
+  }
+}
+
+testNextAuthEndpoints().catch(console.error);