History of checkpointer 2 changes

In crates/hub/src/tlog.rs, lines 691–708 on a0a1601eb5a532d59ffadb89cbe957a7459cca6c44707a8d60aa4e63698b43e9. 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 691,708:crates/hub/src/tlog.rs.