Go buildid reproducibility flag

Trap: CGO_ENABLED=0 go build -trimpath looks like the recorded reproducible build because go version -m exposes those settings, but it does not reveal that the supplied PTY binaries also omit the Go build ID. Fix: build all three with CGO_ENABLED=0 go build -trimpath -ldflags=-buildid= and record the complete command; two independent builds must match each other and the reviewed artifacts.