shell-history-hygiene — Shell-History Audit + Targeted Cleanup

When to invoke

• User explicitly asks to audit / clean / dedup / prune their shell history (atuin or otherwise)
• User pasted an ad-hoc atuin stats / prune / dedup one-liner and asked for review or improvement
• Before any history-store migration (atuin → atuin v2, zsh-only → atuin, etc.) where you want a clean baseline
• During machine-setup audits where the history corpus is being inspected for size or quality

Backends

• atuin (current): atuin stats today, atuin history prune, atuin history dedup
• zsh native (future): .zsh_history line dedup, size limits
• bash native (future): .bash_history line dedup
• mcfly (future): mcfly's own pruning

This skill currently ships the atuin backend at scripts/atuin-audit.sh. Add sibling scripts under scripts/ as backends are added.

How it works (preview-then-apply)