Mirrors the coordinator workflow against a scimesh_users Postgres service.
Switches the test request helper to http.NewRequestWithContext so the noctx
linter passes on the go1.22 module.
- .github/workflows/coordinator.yml: vet, gofmt, race unit tests, golangci-lint,
and the integration suite against a Postgres service — on every push/PR that
touches coordinator/.
- docs/building-workers.md: a from-scratch guide for implementing a worker (the
claim/heartbeat/upload/complete loop, auth, lease semantics, status codes,
and the do-not-break rules), pointing at openapi.yaml for client generation.
- README: refresh the endpoint table, status, and test sections to match reality.
Emil