History of kernel 2 changes

In crates/flow/src/facts.rs, lines 41–49 on 77c8c24066ef11f737fb0dcd1ff02aab93c1b3ead2e65d7e86a548cacdf79833. 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 41,49:crates/flow/src/facts.rs.