feat(sdk): s2s deploy publishes library packages

deploy.ts and client.ts widen to carry a lib artifact alongside s2sp: deployPlugin
branches on packageKind to buildLibrary vs buildPlugin, assembleDeployArchive
becomes kind-aware (a library's types ride inside the .s2lib, so the plugin-only
publishes/types-tarball gate never runs), and client.deploy posts exactly one of
plugin.s2sp / library.s2lib. workspace/deploy-all.ts needed no change, verified by
reading it plus a new test running the real build/plan/upload chain against the
ws-library-in-plugins-glob fixture.