Function finalize_response_for_dispatch_root 

pub fn finalize_response_for_dispatch_root(
    response: &mut Response,
    ctx: &AppContext,
    alerts: &mut AlertEngine,
    session_id: &str,
    dispatch_root: &Path,
    attach_command: &str,
    allow_bg_completions: bool,
)

Finalize an agent-visible response using the root selected by dispatch. The finalizer owns the alert transition and never reads ctx.config().project_root for alert state.