Submodule and worktree checkouts store .git as a file (gitdir: pointer);
the carry-over only looked at directory names, so that form was still lost
on rollback. Handle files with the same guard. Docstring now states the
deliberate limit: an excluded entry whose skill dir the target snapshot
lacks is dropped with staging (no orphan .git) and is not undoable via the
safety snapshot, which excludes these paths as well.
kshitijk4poor
5f24f291c2