Backup Table Snapshot Standard

[Nomad-01]

Migrated from: Nomad-01/powerlab-project#68

Source Project Status: Backlog
Target Project Status: Backlog

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Make intentional backups obvious, not random duplicates.

maybe a folder like
backups/table_snaps/

with a naming pattern like
<table_name><YYYYMMDD_HHMMSS.csv

example
flow_calibration_20260701_160200_before_refactor.csv

done when backup tables rules are documented and old random backups are moved or cleaned.