History of preflight 2 changes

In crates/flow/src/runner.rs, lines 559–583 on 732b4de405e6c078b6de84031e7815b6f5c9faa92046af557ba6d5b2a2341021. 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 559,583:crates/flow/src/runner.rs.