feat(frontend): add usePermission hook, PermissionButton, PermissionRoute, and 403 handling

frontend/src/hooks/usePermission.ts

@@ -0,0 +1,21 @@
+import { useMemo } from 'react';
+
+export function usePermission() {
+  const permissions: string[] = useMemo(() => {
+    try {
+      return JSON.parse(localStorage.getItem('permissions') || '[]');
+    } catch {
+      return [];
+    }
+  }, []);
+
+  const hasPermission = (code: string): boolean => permissions.includes(code);
+
+  const hasAnyPermission = (...codes: string[]): boolean =>
+    codes.some(c => permissions.includes(c));
+
+  const hasAllPermissions = (...codes: string[]): boolean =>
+    codes.every(c => permissions.includes(c));
+
+  return { permissions, hasPermission, hasAnyPermission, hasAllPermissions };
+}