Add wrapper tests for validation wiring through IMiniLcmApi

The validator classes have unit tests, but nothing tested the seam where they meet
the API - which is exactly where #2362 hid (a dead CreateEntry override). These pin
the two things that matter at that seam: methods we expect to validate actually do,
and the ones that deliberately don't (CreateEntry, CreatePublication, CreateMorphType)
keep passing through, so a future "fix" that breaks sync of empty FLEx values goes red.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: myieye

backend/FwLite/MiniLcm.Tests/Validators/MiniLcmApiValidationWrapperTests.cs

@@ -0,0 +1,88 @@
+using FluentValidation;
+using MiniLcm.SyncHelpers;
+using Moq;
+
+namespace MiniLcm.Tests.Validators;
+
+/// <summary>
+/// Tests the validation wrapper's wiring through the IMiniLcmApi interface - the seam that broke in
+/// #2362 - not the validator rules (those have their own unit tests). Two things are worth pinning:
+/// that methods we expect to validate actually do (so a silently-dead override like #2362's is caught),
+/// and that methods which deliberately DON'T validate despite having a validator (CreateEntry,
+/// CreatePublication, CreateMorphType) keep passing through - so a well-meaning "fix" that turns
+/// validation on, and breaks sync of empty FLEx values, trips a red test instead.
+/// </summary>
+public class MiniLcmApiValidationWrapperTests
+{
+    private readonly Mock<IMiniLcmApi> _inner = new();
+    private readonly IMiniLcmApi _api;
+
+    public MiniLcmApiValidationWrapperTests()
+    {
+        _api = TestMiniLcmWrappers.CreateValidationFactory().Create(_inner.Object);
+    }
+
+    private static Entry ValidEntry() => new() { Id = Guid.NewGuid(), LexemeForm = new() { { "en", "lexeme" } } };
+
+    // An entry the EntryValidator rejects: a MultiString that carries an empty value (NoEmptyValues).
+    // This is the shape that routinely arrives from FLEx during sync/import.
+    private static Entry EntryWithEmptyValue() => new()
+    {
+        Id = Guid.NewGuid(),
+        LexemeForm = new() { { "en", "lexeme" } },
+        CitationForm = new() { { "en", "" } },
+    };
+
+    [Fact]
+    public async Task UpdateEntry_BeforeAfter_ValidatesTheUpdatedEntry()
+    {
+        var act = () => _api.UpdateEntry(ValidEntry(), EntryWithEmptyValue());
+
+        await act.Should().ThrowAsync<ValidationException>();
+        _inner.Verify(a => a.UpdateEntry(It.IsAny<Entry>(), It.IsAny<Entry>(), It.IsAny<IMiniLcmApi?>()), Times.Never);
+    }
+
+    [Fact]
+    public async Task CreateSense_ValidatesTheSense()
+    {
+        var sense = new Sense { Id = Guid.NewGuid(), Gloss = new() { { "en", "" } } };
+
+        var act = () => _api.CreateSense(Guid.NewGuid(), sense);
+
+        await act.Should().ThrowAsync<ValidationException>();
+        _inner.Verify(a => a.CreateSense(It.IsAny<Guid>(), It.IsAny<Sense>(), It.IsAny<BetweenPosition?>()), Times.Never);
+    }
+
+    [Fact]
+    public async Task CreateEntry_DoesNotValidate_SoEmptyFlexValuesReachStorage()
+    {
+        var entry = EntryWithEmptyValue();
+
+        var act = () => _api.CreateEntry(entry);
+
+        await act.Should().NotThrowAsync();
+        _inner.Verify(a => a.CreateEntry(entry, It.IsAny<CreateEntryOptions?>()), Times.Once);
+    }
+
+    [Fact]
+    public async Task CreatePublication_DoesNotValidate()
+    {
+        var publication = new Publication { Id = Guid.NewGuid(), Name = new() { { "en", "" } } };
+
+        var act = () => _api.CreatePublication(publication);
+
+        await act.Should().NotThrowAsync();
+        _inner.Verify(a => a.CreatePublication(publication), Times.Once);
+    }
+
+    [Fact]
+    public async Task CreateMorphType_DoesNotValidate()
+    {
+        var morphType = new MorphType { Id = Guid.NewGuid(), Kind = MorphTypeKind.Unknown, Name = new() { { "en", "" } } };
+
+        var act = () => _api.CreateMorphType(morphType);
+
+        await act.Should().NotThrowAsync();
+        _inner.Verify(a => a.CreateMorphType(morphType), Times.Once);
+    }
+}