Function run_command_with 

pub async fn run_command_with(
    cfg: &Config,
    provider_name: &str,
    repo: &str,
    pr: u64,
    cmd: Command,
    backend: &dyn ReviewBackend,
) -> Result<CommandOutcome>

Like run_command but with a caller-supplied ReviewBackend, so /review, /ask, and /describe all run on the same backend (e.g. an agent CLI) instead of always OpenRouter.

Errors

On unknown provider, or any provider/backend failure.