Overall LGTM, aside from minor fixes including updating the API endpoint middleware to check for the prebuilds feature entitlement instead of template RBAC.

One enhancement for future consideration: in the workspace list view, invalidated prebuilt workspaces could display a small indicator icon that shows something like "This prebuild is invalidated and will be removed in the next reconciliation loop" on hover, similar to the outdated workspace indicator (see screenshot). This would be a nice-to-have and can be addressed in a separate PR.

One enhancement for future consideration: in the workspace list view, invalidated prebuilt workspaces could display a small indicator icon that shows something like "This prebuild is invalidated and will be removed in the next reconciliation loop" on hover, similar to the outdated workspace indicator (see screenshot). This would be a nice-to-have and can be addressed in a separate PR.

This is a valid call, but it involves modifying the workspaces endpoint, so definitely another issue/pull request 👍 Thanks for the suggestion!

LGTM ✅ Nice work 🎉