Label chapter chips by kind, not raw number

Beats, tags, locations, open questions, and character/arc-stage
responses that reference a chapter now carry a ChapterLabel/DisplayNumber
alongside the raw Number, computed via the new
ChapterDisplayNumberLookup. Front/back matter chips show their title;
body chapters show "Chapter N: Title".

tests/Novelly.Api.Tests/ListingTests.cs

@@ -85,7 +85,7 @@ public class ListingTests : ServiceTestFixture
         var agent = new NovelAgentService(
             Db.Context,
             new ScriptedModelClient([[new AgentTextBlock("Reply.")]]),
-            new NovelAgentToolset(Novels, Characters, Arcs, Chapters, Beats, Tags, Locations, Questions, NullLogger<NovelAgentToolset>.Instance),
+            new NovelAgentToolset(Novels, Characters, Arcs, Chapters, ChapterLabels, Beats, Tags, Locations, Questions, NullLogger<NovelAgentToolset>.Instance),
             Options.Create(new AgentOptions()),
             NullLogger<NovelAgentService>.Instance,
             new SendAgentMessageRequestValidator());

tests/Novelly.Api.Tests/NovelAgentServiceTests.cs

@@ -12,7 +12,7 @@ public class NovelAgentServiceTests : ServiceTestFixture
     private NovelAgentToolset _toolset = null!;
 
     protected override void OnSetUp() =>
-        _toolset = new NovelAgentToolset(Novels, Characters, Arcs, Chapters, Beats, Tags, Locations, Questions, NullLogger<NovelAgentToolset>.Instance);
+        _toolset = new NovelAgentToolset(Novels, Characters, Arcs, Chapters, ChapterLabels, Beats, Tags, Locations, Questions, NullLogger<NovelAgentToolset>.Instance);
 
     private NovelAgentService BuildAgent(ScriptedModelClient model) => new(
         Db.Context,

tests/Novelly.Api.Tests/ServiceTestFixture.cs

@@ -23,6 +23,7 @@ public abstract class ServiceTestFixture
     protected NovelService Novels { get; private set; } = null!;
     protected CharacterService Characters { get; private set; } = null!;
     protected ChapterService Chapters { get; private set; } = null!;
+    protected ChapterDisplayNumberLookup ChapterLabels { get; private set; } = null!;
     protected BeatService Beats { get; private set; } = null!;
     protected CharacterArcService Arcs { get; private set; } = null!;
     protected OpenQuestionService Questions { get; private set; } = null!;
@@ -75,7 +76,8 @@ public abstract class ServiceTestFixture
             Db.Context, Access, Tags, ActivityLog, CharacterLogs,
             new CreateCharacterRequestValidator(), new UpdateCharacterRequestValidator(), new CreateRelationshipRequestValidator(),
             new LinkCharacterIdentityRequestValidator());
-        Chapters = new ChapterService(Db.Context, Access, Tags, Locations, ActivityLog, ChapterLogs, new CreateChapterRequestValidator(), new UpdateChapterRequestValidator());
+        ChapterLabels = new ChapterDisplayNumberLookup(Db.Context);
+        Chapters = new ChapterService(Db.Context, Access, Tags, Locations, ChapterLabels, ActivityLog, ChapterLogs, new CreateChapterRequestValidator(), new UpdateChapterRequestValidator());
         Beats = new BeatService(
             Db.Context, Access, Tags, ActivityLog, BeatLogs,
             new CreateBeatRequestValidator(), new UpdateBeatRequestValidator(), new ReorderBeatsRequestValidator(),

tests/Novelly.Api.Tests/TagServiceTests.cs

@@ -103,6 +103,29 @@ public class TagServiceTests : ServiceTestFixture
         });
     }
 
+    [Test]
+    public async Task Cross_reference_labels_front_matter_by_title_not_chapter_number()
+    {
+        var foreword = await Chapters.CreateAsync(
+            _novelId, new CreateChapterRequest("Foreword", Number: 1, Kind: ChapterKind.FrontMatter, Tags: ["betrayal"]));
+        var chapter = await Chapters.CreateAsync(
+            _novelId, new CreateChapterRequest("Landfall", Number: 2, Tags: ["betrayal"]));
+
+        var tagId = (await Tags.ListAsync(_novelId)).Single().Id;
+        var tag = (await Tags.GetReferencesAsync(tagId))!;
+        var displayNumbers = await ChapterLabels.ForNovelAsync(_novelId);
+        var references = tag.ToReferencesResponse(displayNumbers);
+
+        var forewordResponse = references.Chapters.Single(c => c.Id == foreword.Id);
+        var chapterResponse = references.Chapters.Single(c => c.Id == chapter.Id);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(forewordResponse.DisplayNumber, Is.Null);
+            Assert.That(chapterResponse.DisplayNumber, Is.EqualTo(1));
+        });
+    }
+
     [Test]
     public async Task Usage_counts_are_reported_per_kind()
     {