History of checkpoint 2 changes

In crates/hub/src/tlog.rs, lines 773–778 on 17dc8de4fca8a9745b17b8c62dff0ad6cf348f62a4524b67cd61561d05a48eef. 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 773,778:crates/hub/src/tlog.rs.