Interface ScanOptions

Persistence boundary, defaulting to diskCacheIO. Pass an in-memory { load, save } (a held cache plus a no-op save) to scan without touching disk — this is how the cache-free all/auto one-shot path works.

Optional progress sink. The CLI wires this to a stderr writer unless --quiet is set.

"owner/repo" pairs to scan

When true, sleep until the rate limit resets and continue, instead of stopping to be resumed later.