test: repair test suite broken by feature drift (red -> 81 passing)

The test project no longer compiled: recent feature commits changed
interfaces and DTOs without updating the test doubles/call sites, so the
whole suite (and therefore CI) was failing to build.

- NoOpInventoryService: add IInventoryService.GetPurchasesSummaryAsync and
  the new string? userId param on AdjustAsync.
- NoOpLoyaltyService: add ILoyaltyService.RedeemOnOrderAsync.
- NoOpOrderNotificationService: add NotifyCallWaiterAsync.
- New NoOpAbuseProtectionService and NoOpMediaStorageService test doubles.
- QrMenuTests: ReviewService/PublicService gained IAbuseProtectionService +
  IHttpContextAccessor (and ReviewService an IMediaStorageService); wire the
  new no-op doubles + a real HttpContextAccessor.
- PrintingTests: OrderDto gained a DisplayNumber int between CreatedAt and
  Items; pass it.
- DiscoverFilterTests: add missing `using Xunit;` and the new openNow arg on
  DiscoverFilterParams.FromQuery.

Result: dotnet test -> Passed: 81, Failed: 0.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/Meezi.API.Tests/NoOpLoyaltyService.cs

@@ -1,4 +1,5 @@
 using Meezi.API.Services;
+using Meezi.Core.Entities;
 
 namespace Meezi.API.Tests;
 
@@ -10,4 +11,11 @@ internal sealed class NoOpLoyaltyService : ILoyaltyService
         decimal paidAmount,
         CancellationToken ct = default) =>
         Task.CompletedTask;
+
+    public Task<(bool Success, LoyaltyRedeemResult? Data, string? ErrorCode)> RedeemOnOrderAsync(
+        string cafeId,
+        Order order,
+        int pointsRequested,
+        CancellationToken ct = default) =>
+        Task.FromResult<(bool, LoyaltyRedeemResult?, string?)>((false, null, null));
 }