A contribution editing a definition its target changed too, apart, is previewed as the merge settles it: merged as text, not a conflict, and merged so. One whose edits are apart but don't typecheck merged is refused, and the target is left as it was (no conflict on it).
a public server: anyone pulls and reads; a contributor's token pushes and proposes only branches under their handle, signed as them; only the maintainer's merges, and removing a contributor stops their token
A server takes code that doesn't typecheck on a contributor's branch, as a client can post it by hand (here: code saved where an implicit any is fine, sent saying it was checked strictly), and refuses to merge it, saying why.
the web UI on tcm serve: the codebase's pages and a contribution's review, rendered on the server in any order, a contributor signed in by the link `tcm contribute` prints, commenting as their handle, and the maintainer merging; a site served beside it keeps its own pages