New Catalog — build the Gym Visual catalog & go live

What "Switch to new catalog" really does: nothing is deleted or rewritten — it only toggles which catalog is offered: old exercises are deactivated, approved new ones are activated (one transaction; search index & AI caches refresh).
• Workout history stays intact — past workouts, sets and records keep rendering exactly as before (they reference exercises by code, and those rows remain in the DB).
• Already-created workouts/plans keep working — existing scheduled workouts still show their old exercises with media and instructions.
• Everything NEW switches — new plans, day regenerations, AI suggestions, search and chat offer ONLY the new catalog from this moment.
• Per-exercise stats start fresh — a new-catalog "Push Up" is a different record than the old one, so its progress/PR counters begin from zero (old ones stay visible on old workouts).
"Roll back to legacy" restores the exact pre-switch state (the same old exercises become active again, new ones deactivate). Workouts created while the new catalog was live are NOT lost — they keep rendering; their exercises just stop being offered for new plans.