feat(adminfront): Implement hierarchical tree view for user group management (Issue #296)\n\n- Refactor TenantGroupsPage.tsx to display user groups in a collapsible tree structure.\n- Add buildGroupTree utility and UserGroupTreeNode recursive component.\n- Update group creation form with parent group selection and unit type.\n- Enhance mutation callbacks with toast notifications for better user feedback.\n- Fix: Add parentId to TenantSummary type in adminApi.ts for type safety.

adminfront/src/lib/adminApi.ts

@@ -27,6 +27,7 @@ export type TenantSummary = {
   description: string;
   status: string;
   domains?: string[];
+  parentId?: string;
   config?: Record<string, unknown>;
   createdAt: string;
   updatedAt: string;