Fix: Correct Novu migration utility query

src/components/admin/NovuMigrationUtility.tsx

@@ -28,16 +28,25 @@ export function NovuMigrationUtility() {
     setProgress(0);
 
     try {
+      // First, fetch user IDs that already have Novu subscriber IDs
+      const { data: existingPrefs, error: prefsError } = await supabase
+        .from('user_notification_preferences')
+        .select('user_id')
+        .not('novu_subscriber_id', 'is', null);
+
+      if (prefsError) throw prefsError;
+
+      const existingUserIds = existingPrefs?.map(p => p.user_id) || [];
+
       // Fetch users without Novu subscriber IDs
-      const { data: users, error: fetchError } = await supabase
+      const query = supabase
         .from('profiles')
-        .select('user_id, users:user_id(email)')
-        .not('user_id', 'in', 
-          supabase
-            .from('user_notification_preferences')
-            .select('user_id')
-            .not('novu_subscriber_id', 'is', null)
-        );
+        .select('user_id, users:user_id(email)');
+
+      // Only add the not filter if there are existing user IDs
+      const { data: users, error: fetchError } = existingUserIds.length > 0
+        ? await query.not('user_id', 'in', `(${existingUserIds.join(',')})`)
+        : await query;
 
       if (fetchError) throw fetchError;