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.

src/Novelly.Api/Common/NovellyServiceRegistration.cs

@@ -1,3 +1,4 @@
+using System.Threading.Channels;
 using Microsoft.EntityFrameworkCore;
 using Novelly.Api.Agent;
 using Novelly.Api.Beats;
@@ -5,6 +6,7 @@ using Novelly.Api.Chapters;
 using Novelly.Api.Characters;
 using Novelly.Api.Common.Validation;
 using Novelly.Api.Data;
+using Novelly.Api.Imports;
 using Novelly.Api.Projects;
 using Novelly.Api.Questions;
 using Novelly.Api.Scenes;
@@ -41,6 +43,14 @@ public static class NovellyServiceRegistration
         services.Configure<AgentOptions>(configuration.GetSection(AgentOptions.SectionName));
         services.AddScoped<IAgentModelClient, AnthropicAgentModelClient>();
 
+        // A single unbounded queue shared by the request path (writer, in ImportService)
+        // and the background runner (reader) — the only background-job infra in the app.
+        services.AddSingleton(Channel.CreateUnbounded<Guid>());
+        services.AddScoped<ImportService>();
+        services.AddScoped<ImportAgentToolset>();
+        services.AddScoped<ImportAgentService>();
+        services.AddHostedService<ImportJobRunner>();
+
         services.AddModelValidatorsFromAssemblyContaining<Program>();
 
         return services;