History of plan 2 changes

In crates/hub/src/diffusion.rs, lines 648–668 on d1bf2d698777c051db9fb656317446513bc0b8ba3c7aadf3c65891c4a96a52c3. 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.