Function dispatch_title 

pub fn dispatch_title(
    agents: Query<'_, '_, (Entity, &RunMetadata), (With<PendingTitle>, Without<AwaitingTitle>)>,
    settings: Option<Res<'_, TitleSettings>>,
    stage: Res<'_, InferenceStage>,
    providers: Res<'_, Providers>,
    sink: Res<'_, TitleSink>,
    commands: Commands<'_, '_>,
)

Dispatch system: start the title call for each PendingTitle run.

A full pool leaves the marker in place to retry next tick; every other dead end (no settings resource, no resolvable provider/model, provider not registered) drops the marker so the query empties instead of spinning.