History of Sky::step 2 changes

In crates/backdrop/src/sky.rs, lines 428–483 on c8684d44d549e0c7c40f0202032904814d318fbb5e75df1c5624225a06dc7668. 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 428,483:crates/backdrop/src/sky.rs.