Function git_work_view 

pub fn git_work_view(
    diff: &GitDiffSnapshot,
    base: Option<BaseState>,
    base_error: Option<&str>,
) -> GitWorkView

The tree behind a row’s depth, as both the record and its frames carry it: the two layers a row draws, with Clean and ScanFailed both reading as nothing to state - which is what the layer means, and the row above still carries the gate that says which.

base is the state the seat’s last watch refresh measured for the layer’s base. It rides the row so a base-only move is news: the range is base..HEAD, so an upstream advance the branch does not contain moves origin/main while the count and the chain stay exactly as they were, and a review page drawing current over it would keep a label nobody re-checked.