Per the updated handbook convention (engineering-handbook PR #18),
reusable-workflow references use full commit SHA pins with a '# main'
comment instead of the mutable @main branch ref. Templates now ship
pinned so new repos start convention-compliant; Dependabot advances
the pin after instantiation. Commented usage examples in ci-static and
ci-typescript-frontend use the <full-commit-sha> placeholder form.
actions/checkout v7.0.0 (2026-06-18) is internally an ESM rebuild plus
one behavioral change: it blocks checking out a fork PR head ref under
pull_request_target / workflow_run (PR #2454). No Sea Haven workflow uses
those triggers, so there is no reachable behavior change. The Node 24
runtime requirement already landed at v6, so v6 -> v7 carries no new
runner requirement. All runners here are GitHub-hosted (ubuntu, macos).
Covers all 16 checkout pins across 12 reusable/standalone workflows plus
the dependency-review workflow-template scaffold. Consumers on @main pick
this up automatically on merge.
