detail
David asked to confirm BACKUP only touches the single file's CURRENT/PREVIOUS/trash and never the platform snapshot. Checking the actual live code revealed this was FALSE for v1.0 — it contained a snapshot-first block that would silently create a full platform snapshot if one didn't already exist that day, before doing the per-file work. Removed entirely per David's direction. BACKUP.php v2.0 now only touches the specific file(s) passed to it — nothing else on the platform, ever. SNAPSHOT remains a fully separate, explicit action (SNAPSHOT.php directly, or REFRESH.php with &save=1). Verified with a real test: captured snapshot ZIP's content-length and last-modified header before and after running BACKUP on Gym Logger — both identical after, confirming BACKUP made zero changes to the snapshot while correctly rotating the Gym Logger backup files.