History of plan 2 changes

In crates/hub/src/diffusion.rs, lines 659–679 on dd0788b756f2d77e53606aef21f1927b97ebdfd6948b7c39d25e71950b77448d. 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 659,679:crates/hub/src/diffusion.rs.