Completes the .prompt/.temp-role split: --prompt set an ad-hoc system role, which is what .temp-role now means everywhere. The --prompt name is left unbound so a future one-shot MCP prompt flag can take it with properly designed non-interactive semantics. use_prompt follows the rename as use_temp_role. BREAKING CHANGE: invocations using --prompt <text> must switch to --temp-role <text>; clap rejects the old flag loudly.