Audit fixes 2026-10-03: seed keeps admin edits, plan cache, refresh limit, payment and tutor guards

- seed_content no longer undoes admin work: a SeedRecord ledger (content/seed_sync.py)
  stops deleted/renamed/re-worded content from being recreated and keeps admin-edited
  lesson text; new rows in the seed files still arrive (migration content.0010)
- plan list cache is invalidated on Plan save (receiver used a stale 'v1' key)
- token refresh per-IP cap 30/hour -> 600/hour (TOKEN_REFRESH_IP_RATE)
- a failed gateway result only changes a pending order (forged NOK no longer
  overwrites refunded/canceled)
- tutor gets the correct answer only after the student has answered
- support reply notification moved to a TicketMessage post_save signal
- global daily cap on paid AI questions (AI_GLOBAL_DAILY_MAX, default 3000)
- Bazaar verify uses only the order's SKU; bazaar orders require a SKU
- /api/health warns on the committed signing key; deploy.sh saves local commits;
  400 for bad ?unit= / ?period=; account delete keeps the referrer's Conversion
- earlier today: no stub answers outside DEBUG, ?grade= removed, logged fallbacks

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

ai_tutor/tests.py

@@ -529,3 +529,20 @@ class StubNeverReachesProductionTests(TestCase):
         )
         self.assertEqual(response.status_code, 503)
         self.assertFalse(Message.objects.filter(conversation__user_id=user.id).exists())
+
+
+class GlobalDailyCapTests(TestCase):
+    """سقفِ روزانه‌ی کلِ سامانه برای سوال‌هایی که به مدل می‌رسند (AI_GLOBAL_DAILY_MAX)."""
+
+    @override_settings(AI_GLOBAL_DAILY_MAX=2)
+    def test_the_whole_system_stops_at_the_daily_cap(self):
+        cache.clear()
+        codes = []
+        for i in range(3):
+            user = User.objects.create(device_id=f'cap-{i}', is_guest=True, name='')
+            codes.append(APIClient().post(
+                '/api/ai/ask', {'userQuestion': f'۲+{i} چند است؟'}, format='json',
+                HTTP_AUTHORIZATION=f'Bearer {issue_access_token(user.id)}',
+                REMOTE_ADDR=f'10.0.0.{i}',
+            ).status_code)
+        self.assertEqual(codes, [200, 200, 503])