Add outline import feature; drop Dto naming, map entities at the API boundary

Services now return entities; endpoints (and the agent toolsets) map to
*Response records instead of services building wire DTOs themselves.
Also brings in the outline-import agent, MCP tool, ledger and web dialog
that were already in progress on disk.

tests/Novelly.Api.Tests/CharacterArcTests.cs

@@ -136,8 +136,8 @@ public class CharacterArcTests : ServiceTestFixture
 
         Assert.Multiple(() =>
         {
-            Assert.That(stage.ChapterTitle, Is.EqualTo("Landfall"));
-            Assert.That(stage.ChapterNumber, Is.EqualTo(1));
+            Assert.That(stage.Chapter!.Title, Is.EqualTo("Landfall"));
+            Assert.That(stage.Chapter!.Number, Is.EqualTo(1));
         });
     }
 
@@ -206,8 +206,8 @@ public class CharacterArcTests : ServiceTestFixture
         Assert.Multiple(() =>
         {
             Assert.That(beats.Select(b => b.Title), Is.EqualTo(new[] { "She finds the map", "She boards anyway" }));
-            Assert.That(beats[0].ChapterNumber, Is.EqualTo(1));
-            Assert.That(beats[0].ChapterTitle, Is.EqualTo("First"));
+            Assert.That(beats[0].Chapter!.Number, Is.EqualTo(1));
+            Assert.That(beats[0].Chapter!.Title, Is.EqualTo("First"));
             Assert.That(beats[1].ChapterId, Is.EqualTo(second.Id));
         });
     }