pub async fn spawn_runtime() -> Result<Runtime, RuntimeError>Expand description
Build the runtime a subagent runs on. Preferred: EngineHost::worker_runtime()
— shares the host credential source and token cache (so NO
set_global_broker re-install and NO token-cache eviction per spawn) and
takes a clone of the cached worker registry template. Legacy path (no host
installed, or kill-switch set): today’s Runtime::new() + rebuilt tools +
apply_auth_config, verbatim.
Called from the subagent’s own OS thread / current-thread tokio runtime:
EngineHost::current() is a OnceLock read and worker_runtime() only
touches tokio::sync primitives, so this is runtime-agnostic.