Subscriptions only: Bazaar panel prices (598/898/1398k), assistant quota 5/3/3 from a cost calculation, packs off sale

- subscription.0016: prices equal to the Bazaar panel (senior), ai_daily_quota 5/3/3, card features; packs on_sale=False
  (one paid pack order, user 26, keeps its credits; pack paths stay for that order and for admin).
- Quota math in docs/ai-cost-and-guardrails.md: ~77% of a Bazaar sale reaches us; worst case (full quota every day)
  the assistant costs 23/27/35% of it.
- Assistant quota message points to the subscription, not packs.
982 tests green.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

payment/tests_bazaar_subscription.py

@@ -59,6 +59,7 @@ class BazaarSubscriptionTests(TestCase):
 
     def test_plan_without_sku_is_refused_for_bazaar(self):
         pack = Plan.objects.get(kind='pack', question_credits=20)
+        Plan.objects.filter(pk=pack.pk).update(on_sale=True)  # بسته‌ها از subscription.0016 فروشی نیستند
         self.assertEqual(self.buy(pack).status_code, 400)
         self.assertFalse(Order.objects.filter(user_id=self.user.id).exists())
 
@@ -82,6 +83,7 @@ class BazaarSubscriptionTests(TestCase):
     def test_pack_verify_asks_for_inapp(self):
         pack = Plan.objects.get(kind='pack', question_credits=20)
         pack.bazaar_sku = 'pack20'
+        pack.on_sale = True
         pack.save()
         body = self.buy(pack).json()
         self.assertEqual(body['bazaarProductType'], 'inapp')