History of Engine::fit 3 changes

In crates/backdrop/src/lib.rs, lines 65–81 on c26267b3aba6b2028df7ba79af75cc09348b112980d46d1e78b209cd446d5497. 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 65,81:crates/backdrop/src/lib.rs.