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>

accounts/views.py

@@ -424,7 +424,9 @@ def _upgradable_guest(request, phone: str):
 
 DELETE_CONFIRM_WORD = 'حذف'
 # سوابقِ پرداخت سندِ مالی‌اند و با حذفِ حساب نمی‌روند (تراکنش‌ها با سفارش می‌مانند).
-KEPT_ON_ACCOUNT_DELETE = ('payment.Order', 'statuslog.StatusChangeLog')
+# Conversion هم می‌ماند: ردیفِ «کاربرِ معرفی‌شده» سابقه‌ی پورسانتِ *معرف* است، نه داده‌ی این
+# کاربر؛ تا ۲۰۲۶-۱۰-۰۳ با حذفِ حسابِ معرفی‌شده پورسانتِ معرف هم پاک می‌شد.
+KEPT_ON_ACCOUNT_DELETE = ('payment.Order', 'statuslog.StatusChangeLog', 'affiliate.Conversion')
 
 
 class DeleteAccountView(APIView):