Update backend to use firebase-admin SDK for FCM

backend/src/modules/tariff/tariff.engine.ts

@@ -6,6 +6,8 @@ export interface QuoteInput {
   waitingMin?: number;
   at?: Date; // لحظة الحساب (لاختيار النافذة الزمنية)
   geofenceMultiplier?: number;
+  /** وزن الحمولة بالكيلوغرام — للشحنات والطرود فقط (L3). */
+  weightKg?: number;
 }
 
 export interface QuoteBreakdown {
@@ -14,6 +16,7 @@ export interface QuoteBreakdown {
   distance: number;
   time: number;
   waiting: number;
+  weight: number;
   bookingFee: number;
   subtotal: number;
   surgeMultiplier: number;
@@ -38,18 +41,21 @@ export class TariffEngine {
 
     if (def.mode === 'fixed_quote') {
       // سعر ثابت متفَق عليه (خط ثابت / وجهة بسعر معلن): لا مسافة ولا زمن.
-      // كان يسقط سابقاً إلى الفرع المتري فيُحسب بالعدّاد رغم اسمه — أي أن
-      // «السعر الثابت» لم يكن ثابتاً أبداً.
       const fixed = Math.max(0, def.fixed_fare ?? 0);
       const waitingOnly = waitingMin * (win.per_min_waiting ?? 0);
-      // الانتظار وحده يُضاف: بقاء الراكب ربع ساعة تكلفة حقيقية على السائق
-      // مهما كان الخط ثابتاً. ولا حدّ أدنى هنا — السعر المعلن **هو** الاتفاق،
-      // ورفعه بحدّ أدنى يعني إعلان سعر وتحصيل غيره.
+
+      // --- L3: وزن الحمولة (شحنات على خطوط ثابتة) ---
+      const weightKg = Math.max(0, input.weightKg ?? 0);
+      let weightCharge = 0;
+      if (def.weight && weightKg > def.weight.free_kg) {
+        weightCharge = (weightKg - def.weight.free_kg) * def.weight.per_kg_above;
+      }
+
       const multiplier =
         (def.surge?.enabled && def.surge.multiplier ? def.surge.multiplier : 1) *
         (input.geofenceMultiplier ?? 1.0);
       const fixedTotal = TariffEngine.round(
-        (fixed + waitingOnly) * multiplier,
+        (fixed + waitingOnly + weightCharge) * multiplier,
         def.rounding,
       );
       return {
@@ -58,8 +64,9 @@ export class TariffEngine {
         distance: 0,
         time: 0,
         waiting: TariffEngine.n(waitingOnly),
+        weight: TariffEngine.n(weightCharge),
         bookingFee: 0,
-        subtotal: TariffEngine.n(fixed + waitingOnly),
+        subtotal: TariffEngine.n(fixed + waitingOnly + weightCharge),
         surgeMultiplier: multiplier,
         total: fixedTotal,
         currency: def.currency,
@@ -84,8 +91,15 @@ export class TariffEngine {
     const waitingCharge = waitingMin * (win.per_min_waiting ?? 0);
     const bookingFee = def.booking_fee ?? 0;
 
+    // --- L3: وزن الحمولة ---
+    const weightKg = Math.max(0, input.weightKg ?? 0);
+    let weightCharge = 0;
+    if (def.weight && weightKg > def.weight.free_kg) {
+      weightCharge = (weightKg - def.weight.free_kg) * def.weight.per_kg_above;
+    }
+
     let subtotal =
-      win.flag + distanceCharge + timeCharge + waitingCharge + bookingFee;
+      win.flag + distanceCharge + timeCharge + waitingCharge + weightCharge + bookingFee;
 
     const surgeMultiplier =
       def.surge?.enabled && def.surge.multiplier ? def.surge.multiplier : 1;
@@ -104,6 +118,7 @@ export class TariffEngine {
       distance: TariffEngine.n(distanceCharge),
       time: TariffEngine.n(timeCharge),
       waiting: TariffEngine.n(waitingCharge),
+      weight: TariffEngine.n(weightCharge),
       bookingFee,
       subtotal: TariffEngine.n(subtotal),
       surgeMultiplier,