History of plan 2 changes

In crates/hub/src/diffusion.rs, lines 659–679 on 026a76d251ce302a7a2851dac1e4301c101948317f11876c3eae5f2942dc2844. 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.