History of Engine::fit 3 changes

In crates/backdrop/src/lib.rs, lines 65–81 on a0a1601eb5a532d59ffadb89cbe957a7459cca6c44707a8d60aa4e63698b43e9. 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.