Introduce templates/pg/pg_base.html holding the common layout, Vazirmatn
typography, colour tokens and reusable components (buttons, rows, dividers,
gateway cards, alerts). All four payer-facing screens now extend it for a
consistent, mobile-first UI matching the approved UI/UX design:
- payment_request: card layout with amount row + gateway picker cards
- payment_confirm: restyled "in review" state
- payment_success: extends base, adds tracking-code row
- payment_failure: extends base, keeps refund notice
Mobile: full-bleed white screen, centred content, primary action pinned to
the bottom with safe-area padding. >=480px: floated centred card on a grey
canvas. No view/logic changes.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
