fix(admin): eliminate GoTrue empty-body 500s under bulk load (retry-all + undici keep-alive + sequential bulk), CSV formula-injection guard

lib/admin/metrics.ts

@@ -1,4 +1,5 @@
 import { getSupabaseAdmin } from '@/lib/supabase/admin';
+import { withAdminRetry } from '@/lib/admin/retry';
 
 export type AdminMetrics = {
   totalUsers: number;
@@ -52,7 +53,9 @@ export async function computeMetrics(): Promise<AdminMetrics> {
   let signups30d = 0;
   const perPage = 1000;
   for (let page = 1; page <= 50; page++) {
-    const { data, error } = await admin.auth.admin.listUsers({ page, perPage });
+    const { data, error } = await withAdminRetry(() =>
+      admin.auth.admin.listUsers({ page, perPage }),
+    );
     if (error) break;
     const users = data.users;
     if (users.length === 0) break;