[stacked on #2387] bb.db retention: archived events, provider/unhandled cap, settled-interaction hygiene - #2393

Actions cache usage is 11.10 GB of 10.00 GB (111%) across 31 entries. GitHub evicts least-recently-used entries without reporting it, so caches are about to start missing. Run `gh cache list --limit 100 --json key,sizeInBytes` to find the job writing oversized entries; a job on a Blacksmith Linux runner should not appear here at all.