feat: интерактивный установщик install.sh (Docker / Ubuntu, админ, БД)

Co-authored-by: Cursor <cursoragent@cursor.com>

src/services/pricing.js

@@ -0,0 +1,66 @@
+const promoService = require('./promo');
+const loyaltyService = require('./loyalty');
+
+async function buildCartPricing(items, session, userId) {
+  const subtotal = items.reduce((s, i) => s + i.line_total, 0);
+
+  let promo = null;
+  let promoDiscount = 0;
+  let promoError = null;
+
+  if (session.appliedPromoCode) {
+    promo = await promoService.findPromoByCode(session.appliedPromoCode);
+    const check = promoService.validatePromo(promo, subtotal);
+    if (!check.ok) {
+      promoError = check.error;
+      promo = null;
+      delete session.appliedPromoCode;
+    } else {
+      promoDiscount = promoService.calcPromoDiscountCents(promo, subtotal);
+    }
+  }
+
+  const afterPromo = Math.max(0, subtotal - promoDiscount);
+
+  let loyaltyBalance = 0;
+  let loyaltyDiscount = 0;
+  let loyaltyPointsUsed = 0;
+
+  if (userId) {
+    loyaltyBalance = await loyaltyService.getBalance(userId);
+    const requested = session.loyaltyPointsToUse ?? 0;
+    loyaltyDiscount = loyaltyService.calcLoyaltyDiscountCents(
+      requested,
+      loyaltyBalance,
+      afterPromo
+    );
+    loyaltyPointsUsed = loyaltyService.pointsForDiscount(loyaltyDiscount);
+  }
+
+  const total = Math.max(0, afterPromo - loyaltyDiscount);
+  const pointsEarned =
+    userId && total > 0 ? loyaltyService.calcEarnedPoints(total) : 0;
+
+  return {
+    subtotal,
+    promoDiscount,
+    loyaltyDiscount,
+    loyaltyPointsUsed,
+    loyaltyPointsUsedDisplay: loyaltyPointsUsed,
+    loyaltyBalance,
+    pointsEarned,
+    total,
+    promo: promo
+      ? {
+          code: promo.code,
+          description: promo.description,
+          discount_type: promo.discount_type,
+          discount_value: promo.discount_value,
+          expires_at: promo.expires_at,
+        }
+      : null,
+    promoError,
+  };
+}
+
+module.exports = { buildCartPricing };