Bug 4: resolveRenewalActivationSubscription - add fallback by user_id+subscribe_id
with SELECT FOR UPDATE when token lookup fails
Bug 5: appleIAPNotifyLogic - return error on product ID mapping failure instead of
silently dropping the notification
Bug 6: NewPurchase fallback query - wrap in transaction with SELECT FOR UPDATE to
prevent concurrent duplicate subscription creation
Bug 7: appleIAPNotifyLogic - fix UserId=0 by reverse-lookup from original purchase
order; create renewal audit order record for DID_RENEW/SUBSCRIBED notifications
Bug 8: UpdateOrderStatus - pre-delete cache before DB write (double-delete) to
close TOCTOU window between DB update and cache invalidation
Bug 9: validateNewUserOnlyEligibilityAtActivation - add Redis distributed lock on
user_id to serialise concurrent new-user-only order activations
Co-authored-by: multica-agent <github@multica.ai>
shanshanzhong147