Two jobs: 'test' runs go vet + go test -race + a Linux smoke build to
catch generic compile errors cheaply. 'build-windows' cross-compiles
drover.exe with version metadata baked in and uploads it as an artifact
with 14-day retention. CGO is disabled - divert-go integration in a
later phase will switch it on with mingw.
Manual git clone (no actions/checkout/setup-go) because the runner's
golang:1.23-bookworm image lacks Node.js. Both jobs cache GOMODCACHE
and GOCACHE keyed by go.sum hash. Concurrency cancel-in-progress keeps
the queue tidy when commits land in quick succession.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>