Ships Pithos (the s3d control panel) as a built-in extension: the dock
menu opens it in a tab served from a loopback port, and "Stop s3d"
shuts the gateway down. Generated by Pithos/scripts/build-theseus-addon.mjs.
yaml is vendored under vendor/yaml/lib rather than node_modules/ or
dist/, because Theseus git-ignores both and a clean-worktree release
build would otherwise ship the add-on without its only dependency.
