Best-effort: if the subscription's latest invoice is still OPEN (a failed renewal), retry it NOW. No-op when there's nothing open to pay; never throws (a fix-billing flow must not 500 on the retry).
Best-effort: if the subscription's latest invoice is still OPEN (a failed renewal), retry it NOW. No-op when there's nothing open to pay; never throws (a fix-billing flow must not 500 on the retry).