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/OpenQuestionTests.cs

@@ -30,9 +30,9 @@ public class OpenQuestionTests : ServiceTestFixture
 
         Assert.Multiple(() =>
         {
-            Assert.That(question.ChapterTitle, Is.EqualTo("Landfall"));
-            Assert.That(question.ChapterNumber, Is.EqualTo(1));
-            Assert.That(question.CharacterName, Is.EqualTo("Ines"));
+            Assert.That(question.Chapter!.Title, Is.EqualTo("Landfall"));
+            Assert.That(question.Chapter!.Number, Is.EqualTo(1));
+            Assert.That(question.Character!.Name, Is.EqualTo("Ines"));
             Assert.That(question.IsResolved, Is.False);
         });
     }