LocalColumnScope

Carries the innermost Column's Compose ColumnScope down the tree, or null when no ancestor Column has provided one yet — read by Modifier.size() to resolve a child's vertical Weight sizing behavior. Provided by ColumnTileRenderer. RowTileRenderer doesn't reset this back to null, so a Row nested inside a Column still sees the outer Column's scope through it — this only matters in practice because Modifier.size() checks LocalColumnScope exclusively for vertical Weight (never for horizontal), so it doesn't affect a Row's own horizontal weight resolution, but a Row's own child declaring a vertical Weight would resolve against the outer Column's scope rather than being ignored. A custom container tile that wants its children to support weight should provide this the same way Column does.