Function apply_single_result 

pub async fn apply_single_result(
    app: &mut App,
    cwd: &Path,
    session: &mut Session,
    worker_bridge: &mut Option<TuiWorkerBridge>,
    result: Result<Session>,
)

Process a single completed session result.

Extracted so both the tokio::select! branch in the event loop and the batch drain path can share the same logic.