Bazaar: subscriptions (10343/10344), dynamic price (discount codes on Bazaar), auto-renewal sync

- Purchase with paymentMethod=bazaar now works for subscription plans with a bazaar_sku (not only packs);
  response carries bazaarProductType. Migration subscription.0014 puts 10343/10344 on the 90/180-day plans.
- Verify asks Bazaar for the right product type (from the order) and stores validUntil (payment.0012).
- POST /api/payment/bazaar/orders/{id}/start: SKU, type, and an HS256 dynamic-price JWT when a discount
  code lowered the price (BAZAAR_DYNAMIC_PRICE_KEY); discount on Bazaar orders allowed only with that key
  and only before start.
- Auto-renewal: sync_bazaar_renewals re-asks Bazaar when the paid period is near its end (status page and
  the paywall via has_subscription_access); each new period becomes a paid order.
- Default BAZAAR_PACKAGE_NAME = com.tadrisino.math.app; health shows bazaarDynamicPrice.
979 tests green. No real Bazaar purchase or renewal tested.

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

.env.example

@@ -111,7 +111,9 @@ BAZAAR_PISHKHAN_API_SECRET=
 BAZAAR_CLIENT_ID=
 BAZAAR_CLIENT_SECRET=
 BAZAAR_REFRESH_TOKEN=
-# BAZAAR_PACKAGE_NAME=ir.tadrisino.app
+# BAZAAR_PACKAGE_NAME=com.tadrisino.math.app
+# کلیدِ «تخفیف پویا» از پیشخان (سمتِ سرور؛ قیمتِ ادمین و کدِ تخفیف را به بازار می‌گوید).
+BAZAAR_DYNAMIC_PRICE_KEY=
 
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 # ۶) اختیاری — پیش‌فرض‌ها معمولاً کافی‌اند