Function handle_spawn_project 

pub(crate) fn handle_spawn_project(
    workspace: &Arc<Workspace>,
    project_name: &str,
    launch_settings: SessionLaunchSettings,
) -> Result<(), String>

Resolve the id the project’s lead will run under, emit SessionUpdate::Spawning under it, then spawn the agent. The Connected event from the resulting SessionTask lands under the same key, so the announced bucket is the one the child connects under. A spawn that fails names the reason, which the heal’s own supervisor counts as a failed attempt; a command dispatch drops it.