Upload learnhub_courses_import_71.json (12 legacy + 59 new courses). All writes are set(…, {merge:true}) — nothing is deleted, and it is safe to run while production is live. Existing user data is never touched.

Maps the ~14 drifted category strings onto the canonical set of 8. Preview first, then apply. Applies merge updates to courses docs only.

Downloads a JSON backup per collection (same format as the Phase 0 console kit).

Merge-restores a backup file created by the export above. Never deletes documents.