Whether a child's own mesh carries a freshness-tracked LEAF type — i.e. it is
a stamped leaf rather than a group subtree (a deferred kind=partition /
nested lod LOD child).
A leaf's per-slice staleness lives in its loadedViewVersion stamp
(isFresh); a group's must be folded from its subtree leaves. This is
the correct leaf/group discriminant — a leaf's committed COUNT can be absent
(not yet committed) even though it is a leaf, so "has a count stamp" is NOT a
safe proxy for "is a leaf".
Whether a child's own mesh carries a freshness-tracked LEAF type — i.e. it is a stamped leaf rather than a
groupsubtree (a deferredkind=partition/ nestedlodLOD child). A leaf's per-slice staleness lives in itsloadedViewVersionstamp (isFresh); a group's must be folded from its subtree leaves. This is the correct leaf/group discriminant — a leaf's committed COUNT can be absent (not yet committed) even though it is a leaf, so "has a count stamp" is NOT a safe proxy for "is a leaf".