feat: implement CSV-based organization chart import and enhance group hierarchy

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

@@ -47,6 +47,7 @@ import {
   removeGroupMember,
 } from "../../../lib/adminApi";
 import { t } from "../../../lib/i18n";
+import { OrgChartUploadModal } from "../components/OrgChartUploadModal";
 
 type UserGroupNode = GroupSummary & {
   children: UserGroupNode[];
@@ -443,13 +444,19 @@ function TenantGroupsPage() {
                 )}
               </CardDescription>
             </div>
-            <Button
-              variant="ghost"
-              size="sm"
-              onClick={() => groupsQuery.refetch()}
-            >
-              <RefreshCw size={14} />
-            </Button>
+            <div className="flex items-center gap-2">
+              <OrgChartUploadModal
+                tenantId={tenantId}
+                onSuccess={() => groupsQuery.refetch()}
+              />
+              <Button
+                variant="ghost"
+                size="sm"
+                onClick={() => groupsQuery.refetch()}
+              >
+                <RefreshCw size={14} />
+              </Button>
+            </div>
           </CardHeader>
           <CardContent>
             <Table>