Rename Project concept to Novel across the stack

Renames the domain concept from Project to Novel throughout the backend
(entities, DTOs, services, endpoints, ProjectAccessService/Permission,
ProjectId foreign keys), MCP server (tool names and routes), and the
React/Vite frontend (types, hooks, routes, components). Adds a new EF
Core migration (RenameProjectToNovel) using RenameTable/RenameColumn to
preserve existing data instead of dropping/recreating tables. Updates
CLAUDE.md's structure section to reference Novels/ instead of Projects/.

src/Novelly.ServiceDefaults/Extensions.cs

@@ -11,8 +11,8 @@ using OpenTelemetry.Trace;
 namespace Microsoft.Extensions.Hosting;
 
 // Adds common Aspire services: service discovery, resilience, health checks, and OpenTelemetry.
-// This project should be referenced by each service project in your solution.
-// To learn more about using this project, see https://aka.ms/aspire/service-defaults
+// This novel should be referenced by each service novel in your solution.
+// To learn more about using this novel, see https://aka.ms/aspire/service-defaults
 public static class Extensions
 {
     private const string HealthEndpointPath = "/health";