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/.

src/Novelly.Api/Agent/NovelAgentService.cs

@@ -10,10 +10,6 @@ using Novelly.Api.Projects;
 
 namespace Novelly.Api.Agent;
 
-/// <summary>
-/// The embedded writing agent. Runs the tool-use loop against the model, persists the
-/// conversation, and returns the finished turn together with a record of what it changed.
-/// </summary>
 public class NovelAgentService(
     INovelDbContext db,
     IAgentModelClient model,
@@ -41,7 +37,6 @@ public class NovelAgentService(
             .ToListAsync(ct);
     }
 
-    /// <summary>Null when no conversation has this id — a lookup miss is expected, not exceptional.</summary>
     public async Task<AgentConversation?> GetConversationAsync(Guid conversationId, CancellationToken ct = default)
     {
         Guard.Default(conversationId, nameof(conversationId));
@@ -51,7 +46,6 @@ public class NovelAgentService(
         return await FindConversationAsync(conversationId, ct);
     }
 
-    /// <summary>True if a conversation was deleted; false if no conversation had this id.</summary>
     public async Task<bool> DeleteConversationAsync(Guid conversationId, CancellationToken ct = default)
     {
         Guard.Default(conversationId, nameof(conversationId));
@@ -69,12 +63,6 @@ public class NovelAgentService(
         return true;
     }
 
-    /// <summary>
-    /// Sends a message to the agent and runs it to completion, executing any tools it
-    /// calls along the way. Returns the assistant's final turn. Null when no project has
-    /// this id, or the request names a conversation that does not exist — a lookup miss
-    /// is expected, not exceptional.
-    /// </summary>
     public async Task<AgentMessage?> SendMessageAsync(
         Guid projectId, SendAgentMessageRequest request, CancellationToken ct = default)
     {
@@ -96,8 +84,6 @@ public class NovelAgentService(
         AgentConversation conversation;
         if (request.ConversationId is { } id)
         {
-            // The id came from the request body, not the route — an unknown id here
-            // is bad input to this call, not a direct "fetch conversation" lookup.
             var found = await FindConversationAsync(id, ct);
             if (found is null)
             {
@@ -111,9 +97,6 @@ public class NovelAgentService(
             conversation = StartConversation(projectId, request.Message);
         }
 
-        // Persist the user's turn before running the loop. The tools save through the
-        // same DbContext, so leaving this pending would entangle it with their writes —
-        // and recording the question even if the model call fails is the behaviour we want.
         await AppendMessageAsync(conversation, AgentRole.User, request.Message, null, ct);
 
         var systemPrompt = BuildSystemPrompt(project);
@@ -141,9 +124,6 @@ public class NovelAgentService(
                 break;
             }
 
-            // Echo the assistant's turn back verbatim, then answer every tool_use block in a
-            // single user turn — splitting the results would train the model out of
-            // requesting tools in parallel.
             transcript.Add(AgentChatMessage.Assistant(response.Content));
 
             var results = new List<AgentContentBlock>();
@@ -182,11 +162,6 @@ public class NovelAgentService(
         return reply;
     }
 
-    /// <summary>
-    /// Appends a turn and commits it. Messages are added to the set directly rather than
-    /// through the parent's collection so their insert never depends on EF discovering
-    /// the graph change at an inconvenient moment.
-    /// </summary>
     private async Task<AgentMessage> AppendMessageAsync(
         AgentConversation conversation, AgentRole role, string content, string? toolCallsJson, CancellationToken ct)
     {
@@ -206,9 +181,6 @@ public class NovelAgentService(
 
         await db.SaveChangesAsync(ct);
 
-        // EF's relationship fixup normally puts the message into the parent's collection
-        // once both are tracked. Guard rather than assume, since the sequence number of
-        // the next turn is derived from it.
         if (!conversation.Messages.Contains(message))
         {
             conversation.Messages.Add(message);
@@ -247,11 +219,6 @@ public class NovelAgentService(
         return conversation;
     }
 
-    /// <summary>
-    /// Replays the stored conversation as plain text turns. Tool calls are not replayed —
-    /// the agent re-reads current state through its tools, which is more reliable than
-    /// trusting a transcript of edits that may since have been changed in the UI.
-    /// </summary>
     private static List<AgentChatMessage> BuildTranscript(AgentConversation conversation) =>
     [
         .. conversation.Messages
@@ -273,8 +240,8 @@ public class NovelAgentService(
         return $"""
             You are a developmental editor and writing partner embedded in the software the
             writer is using to plan their novel. You have tools that read and write the
-            project's real data: the brief, character dossiers, the outline tree, chapters
-            and scenes.
+            project's real data: the brief, character dossiers, the outline (beats) and each
+            chapter's drafted prose.
 
             The project you are working on:
             {brief}
@@ -291,8 +258,8 @@ public class NovelAgentService(
             - Prefer structural help — where a beat lands, whether a want and a need are
               genuinely in tension, what the outline is missing — over line-level polish,
               unless the writer asks for prose.
-            - When drafting prose into a scene, match the voice already established in the
-              project. Write the scene, then stop; do not append notes about your choices.
+            - When drafting a chapter's prose, match the voice already established in the
+              project. Write the chapter, then stop; do not append notes about your choices.
             - Destructive operations (deleting outline nodes) need the writer's explicit
               go-ahead first.
 
@@ -300,7 +267,6 @@ public class NovelAgentService(
             """;
     }
 
-    /// <summary>Derives a conversation title from its opening message.</summary>
     private static string Summarise(string message)
     {
         var trimmed = message.Trim().ReplaceLineEndings(" ");