History of gc 3 changes

In src/cli/workspace.rs, lines 254–277 on 2b872d074ddb4dd751e6a78161dac263dd6f5af7ec1d206bb288f084bedcf494. 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 254,277:src/cli/workspace.rs.