ycb_django_pr14725

what a new run launched now would send

Provide a way for model formsets to disallow new object creation
Description
	
Model formsets don't provide a way to create an "edit only" view of objects. We see users trying to use extra=0 to accomplish this, but that's not reliable as extra is merely meant for the extra number of forms to display. You can add more forms with Javascript (or just send additional post data).

Work only inside this repository checkout. Make the code change the task
describes, keeping the diff focused — no drive-by refactors.

When you are done, leave your changes committed or in the working tree;
they are collected automatically.

Stay on this snapshot checkout (`task/ycb_django_pr14725`). Never checkout, pull, or rebase onto `main`. That branch is a README-only orphan.
Stay on this HEAD. Do not fetch another default branch. Push only on the Cursor-created `crazy-cursor/…` side branch from this HEAD.

Some past runs of this task were launched with a different prompt (the prompt template changed since, or those runs predate this benchmark's stored prompt). Each run persists the exact prompt it sent at launch — that per-launch record is the audit trail; this page shows only the current one.