feat: implement onboarding flow with complex creation and email verification, and add Zustand for state management

apps/frontend/src/routes/auth-callback.tsx

@@ -1,7 +1,7 @@
-import { useEffect } from 'react';
 import { apiClient } from '@/lib/api-client';
 import { useAuth } from '@/lib/auth';
 import { createFileRoute, useNavigate } from '@tanstack/react-router';
+import { useEffect } from 'react';
 
 function AuthCallbackPage() {
   const navigate = useNavigate();
@@ -28,10 +28,10 @@ function AuthCallbackPage() {
             navigate({ to: '/select-complex' });
           }
         } else {
-          navigate({ to: '/' });
+          navigate({ to: '/onboard/create-complex' });
         }
       } catch {
-        navigate({ to: '/login' });
+        navigate({ to: '/onboard' });
       }
     }
 
@@ -47,4 +47,4 @@ function AuthCallbackPage() {
 
 export const Route = createFileRoute('/auth-callback')({
   component: AuthCallbackPage,
-});
+});