The sam-deploy starter template pointed every new repo's cfn-role-arn at
the management account's execution role, silently landing new workloads
in an account frozen for workloads. The ARN is now a REPLACE-ME
placeholder with guidance to use the github-cfn-execution-role in the
repo's target account.
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.
Add job-level concurrency (cancel-in-progress) to all four ci-python-app
jobs, matching the ci-python-sam idiom. Per-job group keys include
github.job so the parallel jobs in a single run do not share a group.
Replace sam-deploy starter-template stack-name: $default-branch (which
GitHub substitutes to the literal branch name main) with a
REPLACE-ME-stack-name placeholder, and point cfn-role-arn at the real
shared github-cfn-execution-role.
