Question packs removed at the root; all subscriptions 4 assistant questions a day; Bazaar is subscription-only

- subscription.0017/0018, payment.0013: pack plans deleted, QuestionCredit/HeartsPass models and Plan.kind /
  question_credits / hearts_days / Order.question_credits / hearts_days dropped. The only paid pack order was the
  company owner's test account (user 26).
- Assistant: no credit spending; quota is the daily cap only (free 2, every plan 4, gift subscription 4).
- Bazaar: verify_purchase is subscription-only (no inapp guess), start/purchase responses lose productType,
  verify refuses an order without a subscription. A paid order with no subscription now logs ERROR.
- Removed POST /api/payment/orders (internal; no caller). Its permission tests stay.
- Pack-based tests rewritten on subscriptions (refund, security, Bazaar token); pack-only test files deleted.
- docs: profit table for 4/day on both payment routes plus free users; handbook, operations, CLAUDE.md current.
949 tests green.

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

payment/providers.py

@@ -87,8 +87,7 @@ class BazaarProvider(PaymentProvider):
         return None
 
     def purchase_extras(self, order, plan) -> dict:
-        return {'bazaarSku': order.bazaar_product_sku,
-                'bazaarProductType': 'subscription' if plan.kind == 'subscription' else 'inapp'}
+        return {'bazaarSku': order.bazaar_product_sku}
 
     def discount_blocker(self, order) -> str | None:
         from . import bazaar