Drive the payment countdown from the booking's expires_at (15-min lock)
instead of a fake local 10-min timer; when it hits zero, show an expiry
notice and an 'choose time again' button back to slot selection. Show the
booked time (Jalali) and doctor on the payment step, and replace the
fabricated success amount with a confirmation/SMS note.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
POST /api/v1/payment/appointment expects { appointment_uuid, gateway,
frontend_address } and returns data.redirect_url. Send that body, redirect
to the gateway URL the backend returns (instead of hand-building one),
align the bank options with the real mellat/sep gateways, and remove the
hard-coded 10,000 toman amount (no real price available at this step).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>