History of Sky::step 2 changes

In crates/backdrop/src/sky.rs, lines 428–483 on a74ba3cb45110de2d93ca6a30715294f4a59b6bdf7f1b957125985b4dcb9794c. 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.