The release record leaves the tree: releases live in the database or on an annotated tag, not in src/core/releases.json #6642

Split from #6640 (item 1). A release cut must not push a commit to main. Move the record (version, migrations, ids) to the database and an annotated v0.7.N tag (message = JSON), or a releases ref main never merges; read it from there in src/web/standards.ts, src/spawn/heartbeat.ts, src/release/behind.ts; move test/standards.test.ts, test/schema-additive.test.ts checks with it; change the release cutter. Once done, movedDisjoint in src/checks/queue.ts no longer needs the releases.json exemption.

Files: src/core/releases.json, src/web/standards.ts, src/spawn/heartbeat.ts, src/release/behind.ts, test/standards.test.ts, test/schema-additive.test.ts, scripts/pin-migrations.ts

Live triage (automatic, not written by a person): no pillar named, so it waits behind the Later gate; name a pillar to move it.

Pillar named: P0 Trust. A release cut that commits to main voids every merge gate in flight, the same gate work as #6533, #6534 and #6494. #586 now waits for this issue and for its split-off #6646 (migration pins), and this issue no longer waits behind the Later gate #595, which had made the link a loop. The parent #6640 is still behind the gate; that is the call of whoever owns it.