History of plan 2 changes

In crates/hub/src/diffusion.rs, lines 213–233 on 7a14bdaeb857c2c83237194d212adeb59a19ce96dab5517fde6c89b05f786516. 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 213,233:crates/hub/src/diffusion.rs.