fn seat_tree_scope(scope: &ReviewScope) -> ReviewScopeExpand description
The caller’s seat-tree scope, derived from its resolved branch scope:
project, author label and caller carry over; the key is the seat’s own
tree (a worker’s worktree, the lead’s checkout), which is where the
files page’s reviews live. The tools consult it beside the branch on
their default (no scope argument) path.