pub async fn print(
harness: &AgentHarness,
_args: &Args,
initial: Option<String>,
extra_messages: &[String],
initial_images: Vec<ImageContent>,
) -> i32Expand description
print mode: send the initial message (prompt text + inline @file
expansions), then any follow-up messages, print the final assistant text,
return the exit code. Mirrors TS runPrintMode (text).