PR limit overrides: clearer repo controls and bug fix

[moraesc]

We’ve updated the organization- and repository-level pull request limit override flow, and fixed a related issue reported by users.

1. Repository admins can now override organization-level PR limits — Repositories inheriting organization-level PR limits will show a banner explaining that they’re using the organization’s settings. Repository admins can now configure repository-level limits to override those settings, or clear the repository-level limits to resume inheriting from the organization.

2. We fixed a bug where repository-level overrides appeared to work but didn’t stick — When a repository was inheriting settings from its organization, the override controls appeared to save successfully. However, after refreshing the page, the repository reverted to the organization’s settings. This silent failure is now fixed.

These changes give organizations a consistent default while allowing individual repositories to choose the policy that works best for their maintainers and contributors. Drop a comment if you have any questions or run into any other issues.