Fixed: Retry now explains why a payment retry was refused

Pressing Retry now on a failed payment sometimes did nothing but show "Couldn't queue retry. Try again," with no explanation, even on a deliberate refusal. One merchant pressed it four times on the same failed payment in one day and got that message every time.

Retry now, both on a single subscription and in a bulk action across several subscribers at a shop, now names the specific reason a retry is refused: that a retry attempt is already in flight, that the payment is billed by invoice, that the shop has renewals paused, or that Smart Recovery has already paused the shop, including inside the result of a bulk Retry now run.

These were genuine, deliberate refusals, not errors: every one previously surfaced as a generic error even though Subi was behaving correctly. The fix only changes what the message says; it moves no charge and changes nothing about when a retry actually runs. 12 shops are in a paused-recovery state today, and pressing Retry now there now shows why instead of a dead end.