Decide & stage removal of waffle flag: `enableCourseOptimizer`

• Flag name: enableCourseOptimizer
• Flag details: Gates the Course Optimizer page (broken-link checker, found in Studio's Tools menu).
• Removal date: It has been passed (2025-05-30).
• Current status: Currently disabled by default; can be enabled via the waffle flag contentstore.enable_course_optimizer.

Feature Details:

Course Optimizer — a Studio tool (under the Tools menu) that scans a course for broken links and helps authors fix them. It also has sub-feature flag enableCourseOptimizerCheckPrevRunLinks

What to do in this ticket

1. Involve stakeholders / product owners to discuss and decide on the future of this flag.
2. If we decide to enable it by default:
   1. Enable it by default in openedx-platform.
   2. Roll it out and gather feedback from the community.
   3. As a follow-up step, remove the waffle flag controlling this feature — provided we confirm it should remain an out-of-the-box feature.

Testing Notes:

Testing notes are give in comment below

References

• Original feature PR: openedx/frontend-app-authoring#1533
• Flag PR: openedx/openedx-platform#35884
• Community proposal: openedx/platform-roadmap#388

/cc @jesperhodge — what are your thoughts on the removal of this flag?