History of signer_line 1 change

In src/cli/mcp.rs, lines 416–434 on c397a8c36a9f9b5249938b0715447836232c970d76d3952cd95a95d1282eaca3. 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 416,434:src/cli/mcp.rs.