feat: implement custom login system with direct authentication

- Add custom login page with username/password form and SSO fallback
- Implement direct login API endpoint with security features
- Add forgot password functionality and email notifications
- Create guest middleware for authentication routing
- Update Keycloak configuration and add cookie domain settings
- Add security utilities for rate limiting and validation
- Include comprehensive documentation for custom login implementation

middleware/guest.ts

@@ -0,0 +1,8 @@
+export default defineNuxtRouteMiddleware((to, from) => {
+  const { user } = useAuth();
+  
+  // If user is already authenticated, redirect to dashboard
+  if (user.value) {
+    return navigateTo('/dashboard');
+  }
+});