Runs a Loop now, out of band, in addition to its cron fires. With triggerName, the run carries that cron trigger's name and overrides; without it, the run uses the Loop's declared action, so a Loop with no cron trigger can be run too. A factory stage, which runs only when its event arrives, is refused with 400. The launch run is created asynchronously. Runs a preflight over the run's config first; on a config problem (deleted environment, missing GitHub token, uninstallable skill, unreachable repo, the named trigger's invalid cron) it returns 422 without running. Answers 202 once the launch run is created, or with waiting set when the run was accepted and is waiting for its debounce window or behind a held concurrency key; 409 when the run is refused.