History of Sky::layout 3 changes

In crates/backdrop/src/sky.rs, lines 304–343 on v0.9.23. Every change that wrote or deleted one of these lines, or deleted a line from between them. Exact, because each line keeps its identity across edits; edits elsewhere in the file are not here. Also: oxy log -L 304,343:crates/backdrop/src/sky.rs.