History of plan 2 changes

In crates/hub/src/diffusion.rs, lines 648–668 on f0f6c2d96b1cbdde9c994fe79244bfc4237f3392fc53c71abc5537085c745353. 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 648,668:crates/hub/src/diffusion.rs.