pub fn emit_error_json(code: i32, message: &str)Expand description
Emits a JSON error envelope to stdout for machine consumers.
Ensures the stdout JSON contract is honoured even on error paths:
{"error": true, "code": <exit_code>, "message": "<localized_msg>"}.
A BrokenPipe error is silenced so piping to early-closing consumers
does not surface a secondary error.