History of plan 2 changes

In crates/hub/src/diffusion.rs, lines 436–456 on 1656dc14c2ac72212fd969ea185b8be449aff000a45b3956f1cf51d156132dbe. 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 436,456:crates/hub/src/diffusion.rs.