Updated PLANS.md, AGENTS.md, and arabic-localization.md to reflect the “foundations now, full translations later” approach and marked progress accordingly.

Implemented localization foundations across backend and frontend (locale settings/middleware, preferred language, i18n wiring, RTL support, minimal Arabic UI strings, Accept-Language).
Added targeted backend and frontend tests plus a risks note for pending full translation coverage.

backend/apps/payments/serializers.py

@@ -1,4 +1,5 @@
 from rest_framework import serializers
+from django.utils.translation import gettext_lazy as _
 
 from apps.bookings.models import Booking
 from apps.payments.models import Payment, PaymentProvider, PaymentStatus
@@ -33,7 +34,7 @@ class PaymentCreateSerializer(serializers.ModelSerializer):
 
     def validate_booking_id(self, value):
         if not Booking.objects.filter(id=value).exists():
-            raise serializers.ValidationError("Booking not found")
+            raise serializers.ValidationError(_("Booking not found"))
         return value
 
     def create(self, validated_data):

backend/apps/payments/views.py

@@ -1,5 +1,6 @@
 from rest_framework import permissions, status, viewsets
 from rest_framework.response import Response
+from django.utils.translation import gettext as _
 
 from apps.bookings.models import Booking
 from apps.payments.models import Payment
@@ -39,11 +40,11 @@ class PaymentViewSet(viewsets.ModelViewSet):
         serializer.is_valid(raise_exception=True)
         booking = Booking.objects.get(id=serializer.validated_data["booking_id"])
         if not user_can_access_booking(request.user, booking):
-            return Response({"detail": "Not allowed"}, status=status.HTTP_403_FORBIDDEN)
+            return Response({"detail": _("Not allowed")}, status=status.HTTP_403_FORBIDDEN)
         payment = serializer.save()
         return Response(
             {
-                "detail": "Payment record created. Provider integration pending.",
+                "detail": _("Payment record created. Provider integration pending."),
                 "payment_id": payment.id,
                 "amount": str(payment.amount),
                 "currency": payment.currency,