fix: package-based compliance audit — feature DIFF, remove hardcoded fallbacks

- ActivateClubMembership: replace GetAllFeatureIds with PackageFeature DIFF (Q20)
- ActivateClubMembership: fix re-activation early return — check current cycle
- AcceptClubMembershipContract: same feature DIFF logic
- VerifyPackagePurchase: remove ?? 2.0m fallback, throw if package null
- PackageService: remove ?? 2.0m fallback for DiscountMultiplier
- UserOrderService: remove ?? 1B fallback for MagicWalletMaxDeposit
- SystemConstants: remove 9 dead [Obsolete] constants (per-package values)

src/CMSMicroservice.WebApi/Services/PackageService.cs

@@ -314,7 +314,9 @@ public class PackageService : PackageContract.PackageContractBase
                 await _context.SaveChangesAsync(context.CancellationToken);
             }
 
-            var discountAmount = (long)(purchase.Amount * (double)(purchase.Package?.DiscountMultiplier ?? 2.0m));
+            var discountMultiplier = purchase.Package?.DiscountMultiplier
+                ?? throw new RpcException(new Status(StatusCode.Internal, "پکیج سفارش یافت نشد"));
+            var discountAmount = (long)(purchase.Amount * (double)discountMultiplier);
             wallet.Balance += purchase.Amount;
             wallet.DiscountBalance += discountAmount;