History of checkpoint 1 change

In crates/hub/src/flow.rs, lines 1440–1456 on aeed63c00ad7ae8ee6a978b0615d273306d8378a1c279b05fb4b5bc86802bddc. 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 1440,1456:crates/hub/src/flow.rs.