The cgo wiring links libghostty-vt statically by default and uses -tags dynamic to opt into the shared library, as the README says.
doc.go still described the reverse, and the Buildkite pipeline built with -tags static, which I thought was confusing. It's not a recognized tag, so it ran the default build twice.
I've also updated the package doc and made the CI step use -tags dynamic so both link modes are actually tested. . If you want to go in one direction, I can remove this, but I'm currently playing around with a local project that consumes both.