[Mat4m0]

What changed

• New workflow Retry runner shortages (.github/workflows/retry-runner-shortage.yml). When an Application verification, client canary or client recertification run fails, it checks why. If every failed or cancelled job was either cancelled with "not acquired by Runner" or is the verify / verify gate that fails as a result, it reruns the failed jobs. It stops after three attempts in all.
• A short note under "GitHub enforcement" in docs/development-workflow.md.

Why

GitHub's macOS arm64 pool is short of machines. A job that waits too long is cancelled, and verify / verify turns red although no test ran. Since Nov 1 this has hit #539 (three manual reruns), #544, #537, #541, both main runs (d6d046f, 70cb19f) and the client recertification. Every case needed a manual gh run rerun --failed.

Safety

• It never reruns a real failure. A failed test, a failed audit, a failed install, or a cancellation for another reason (such as a newer push) stops the retry.
• It reads job results and annotations only. It does not check out or run PR code, so fork PRs are safe. Its permissions are actions: write and checks: read.
• Versioned release is not covered; a release rerun stays a manual decision.

Verification

• actionlint passes. pnpm test:policy passes (188 tests).
• The run script was replayed against real runs from today, with the rerun call replaced by an echo:

Run	Situation	Result
41663036291 (#544)	3 jobs not acquired	rerun
41622716010 (recertification)	derive not acquired	rerun
41634472759 (#537)	3 jobs not acquired	rerun
41631535647 (#537)	audit + Electron shard failed	no rerun
41612162024 (#537)	cancelled by a newer push	no rerun
41643011855 (Dependabot)	install failed	no rerun
41635280475 (#540)	audit failed + 1 not acquired	no rerun
invalid run ID	API 404	step fails

• Not verifiable before merge: a workflow_run workflow runs only from the default branch. The first real shortage after merge is the live test. If GitHub does not trigger workflow_run for a rerun started by the workflow token, the limit is effectively two attempts instead of three.

🤖 Generated with Claude Code