Centralize Go validation and build environments

docs/consumers/check.md

@@ -25,8 +25,14 @@ product name and exact version as complete title elements. No local tag with
 that version may already exist.
 
 The callback receives the captured repository, commit, and version. ReleaseKit
-calls it once. When omitted, ReleaseKit runs the offline Go test command. The
-check revalidates the branch, commit, and cleanliness after validation.
+calls it once. When omitted, ReleaseKit runs
+`go test -mod=readonly -count=1 ./...` with the available compatible local Go
+toolchain; it does not download a different toolchain automatically. The suite
+uses the Go host target, disables workspace and module network access, and
+ignores ambient `GOFLAGS`, experiment, and CPU feature overrides. Effective
+cache and native cgo/C-tool settings are preserved, including values from Go's
+persistent environment file. The check revalidates the branch, commit, and
+cleanliness after validation.
 
 A successful check is evidence about the local candidate only. It does not
 check whether a remote branch or tag is available and does not create a tag.