History of mark 2 changes

In crates/hub/src/diffusion.rs, lines 181–183 on 85ec74fd82d8075b2e48d1383547cc3a18886327bb29b28f08c58d8a29929fad. 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 181,183:crates/hub/src/diffusion.rs.