fix: follow rules of hooks in TenantSchemaPage

adminfront/src/features/tenants/routes/TenantSchemaPage.tsx

@@ -58,7 +58,10 @@ export function TenantSchemaPage() {
 
   const tenantQuery = useQuery({
     queryKey: ["tenant", tenantId],
-    queryFn: () => fetchTenant(tenantId!),
+    queryFn: () => {
+      if (!tenantId) throw new Error("Tenant ID is required");
+      return fetchTenant(tenantId);
+    },
     enabled: !!tenantId && canAccess,
   });
 
@@ -94,6 +97,8 @@ export function TenantSchemaPage() {
 
   const updateMutation = useMutation({
     mutationFn: (newFields: SchemaField[]) => {
+      if (!tenantId) throw new Error("Tenant ID is required");
+
       // Remove legacy loginIdField, keep isLoginId natively in userSchema
       const newConfig = { ...tenantQuery.data?.config };
       newConfig.loginIdField = undefined;