phase1: RLS simplified to tenant isolation only + canAccess fallback removed + useUserPermissions hook + security kernel docs

frontend/src/hooks/useAuth.ts

@@ -1,11 +1,15 @@
 import { useEffect } from 'react';
 import { useAuthStore } from '@/store/authStore';
 import { useCurrentUser } from '@/api/hooks';
+import { useUserPermissions } from '@/hooks/useUserPermissions';
 
 export function useAuth() {
   const store = useAuthStore();
   const { data, isLoading, isError, error } = useCurrentUser();
 
+  // Load permissions after authentication
+  useUserPermissions();
+
   useEffect(() => {
     if (isError) {
       const status = (error as any)?.status || 0;