Completes the four POS v2 roadmap items:
1. Real split payments — split tab records N separate payment rows (equal split,
last row takes the remainder), each row toggles Cash/Card; posts payments[].
2. Card-terminal push — confirmPay sums Card amounts and calls requestPosPayment
(POS device) before recording; surfaces POS_DEVICE_* errors.
3. Customer + coupons + loyalty — reuses PosCustomerPicker (attach/search/create)
and validates coupons via /coupons/validate (discount in totals). Pay sheet
offers loyalty redemption (1 point = 100 toman) when a customer is attached.
4. Promote to default — /pos now renders POS v2 (full-screen, café-themed); the
classic terminal moves to /pos-classic with its sidebar+topbar chrome. The
"نسخه کلاسیک" link points there.
Order submission already carried customerId/guestName/guestPhone/couponId via the
shared cart store, so customer + coupon flow straight through send + pay.
tsc --noEmit clean.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
soroush.asadi