Function scope_receipts 

pub async fn scope_receipts<F>(
    scope: Option<ReceiptScope>,
    fut: F,
) -> <F as Future>::Output
where
    F: Future,

Scope TOOL_LOOP_RECEIPT_CONTEXT around fut for the lifetime of one turn so delegate sub-loops forward receipts into the same per-turn collector. One seam shared by every entrypoint; a None scope is inert.