db/specs/appevents-pruner-design.md:90 still names bare app.user_id GUC, stale since terra_23

terra_23 (2026-08-16) hard-cut app.user_id/app.archive_reason to app.terraUserId/app.terraArchiveReason. db/backup-db.sh and db/schema.md were corrected in the same push (a621cb6). db/specs/appevents-pruner-design.md:90 was deliberately left out by coder-terra-cc because the file currently carries 87 uncommitted insertions from another lane and --only is per-file, not per-hunk — including it would have committed someone else's in-progress work under this commit's Authored-By. Descriptive prose only (actor-uuid provenance description, not an operator instruction), lowest urgency of the three stale surfaces found. Close condition: line updated to the prefixed GUC pair, by whoever owns the file's current uncommitted edit, after it lands.