Remove Scenes, group beats by multiple characters; strip comments repo-wide

Drop the Scene entity/grouping in favor of chapters carrying prose directly
and beats belonging to many characters. Add markdown editor + character
multi-select components to the web client. Remove all XML doc and inline
comments across the touched C#/TS/CSS files in favor of self-documenting
names, and record that convention in CLAUDE.md. Add .mcp.json (local MCP
server config, no secrets) and ignore .idea/.

tests/Novelly.Api.Tests/ImportServiceTests.cs

@@ -105,7 +105,6 @@ public class ImportServiceTests : ServiceTestFixture
 
         Assert.That(second.Id, Is.EqualTo(first.Id));
 
-        // Only one job was ever queued.
         Assert.That(_queue.Reader.TryRead(out _), Is.True);
         Assert.That(_queue.Reader.TryRead(out _), Is.False);
     }