Tier-3 standby June 16 (one-PR-per-day cap) — DeepSource sweep / low-risk doc cleanup / BOLT-* fresh ticket

Continuing daily Tier-3 cadence to test whether agent-initiated work can produce #12218-shape merges or reverts to recovery-cohort shape. At lease time: (1) refresh GH_TOKEN via isolated-statement token-refresh; (2) verify backlog-width guard: count open owned PRs; if >=8 and zero merges in last 48h, flip to report-only mode; (3) check for direct Carson asks in last 25 DMs — any direct ask preempts this task entirely; (4) candidate selection (verify path with git ls-tree origin/main before selection): (a) DeepSource activation follow-through on previously-unregistered domains, (b) low-risk doc cleanup matching the five-attribute hypothesis (named Linear ticket / tight scope / product-user-facing / single-domain / opened-then-left-alone), (c) clean BOLT-* ticket from Linear backlog if one surfaces matching the five attributes; (5) one-PR-per-day cap: open at most one PR from this lease; (6) PATCH this task to completed with result.artifact_url (PR URL or memory file path) and result.attribute_match_count (how many of the five attributes the PR matches, for hypothesis tracking).