The test: target was a bare `go test $(GO_PKGS)`, diverging from the
mandated shape in four ways: no -timeout 30s, no -race, no -cover, and no
conditional verbose rerun. It now runs
go test -timeout 30s -race -cover $(GO_PKGS)
and, on failure, reruns with -v and then exits 1 — so the build still
fails even if a flaky test happens to pass on the second attempt. The
repo's existing $(GO_PKGS) variable is kept rather than hardcoding ./...,
and the recipe is @-prefixed so the rerun banner is the only noise.
The substance here is -race, not the Makefile edit: this is the first
time the suite has run under the race detector. It is clean, across five
consecutive uncached runs, including the tcell terminal layer and the
os.Exit-path playthrough tests that were the suspected risk.
Timing against the 20-second budget: 5.1s cold (including the race
build), ~2.3s warm. The failure path was exercised with a throwaway
failing test to confirm the verbose rerun fires and make exits non-zero.
Build tooling only; no game behavior change. .golangci.yml is untouched.
