no-hearts screen: live countdown, filling heart, auto-continue; refunded/canceled invoices

- The wait screen counts down to the next heart second by second, fills
  the first heart as time passes, shows when all five are back, and asks
  the server when the time comes; 'continue' reloads the quiz. Packs and
  'ask Pi meanwhile' (asking costs no hearts) are offered as ways on.
- The server now also refuses to finish a lesson/island without hearts
  and answers (403 no_hearts); the quiz shows the same screen then.
- Invoices know the two admin-set statuses, canceled and refunded.
- Account deletion waits for all six digits of the SMS code.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/screens/ProfileScreen.tsx

@@ -381,7 +381,7 @@ function DeleteAccountSheet({ open, onClose, onSignedOut }: { open: boolean; onC
           <PrimaryButton
             color="#ef4444"
             loading={busy}
-            disabled={needsCode ? value.length < 4 : value.trim() !== 'حذف'}
+            disabled={needsCode ? value.length < 6 : value.trim() !== 'حذف'}
             onClick={() => void remove()}
           >
             حذفِ همیشگی