Reorganise by feature, rename to Novelly, add Aspire and a pre-push hook

The layered split into Domain/Application/Infrastructure/Api was forcing
organisation by layer: adding one capability meant touching four projects and
four folders that each held a slice of it. Those four projects are now one
feature-organised Novelly.Api, where each folder — Projects, Characters,
Chapters, Beats, Scenes, Tags, Agent — holds its entity, DTOs, service and
endpoints together. Common/ holds what genuinely crosses features (the patch
semantics, the two exception types, DraftStatus) and Data/ holds the DbContext
and migrations.

Six .NET projects become five: the three layer projects are gone, and
Novelly.AppHost and Novelly.ServiceDefaults are new.

- Namespaces move from NovelSoftware.* to Novelly.*, including the entity type
  names recorded in the EF model snapshots. The migration ids are untouched, so
  an existing novel.db still migrates cleanly — verified against a fresh file.
- Aspire orchestration mirrors the mic-check setup: the AppHost starts the API
  on :5080 and the Vite dev server on :5173, and the API picks up OpenTelemetry,
  health checks and service discovery from ServiceDefaults. /health and /alive
  now answer in development.
- A Husky pre-push hook runs scripts/ci/prepush.sh: build, test, then a web
  build. The scripts are plain bash so CI can run the same steps.
- The MCP server's env var is now NOVELLY_API_URL.

Verified beyond the build: 44 tests pass, the web client builds, the API was
exercised over curl (project/chapter/beat/tag round trip, tag cross-reference,
503 on the agent without a key while conversation listing still returns 200),
the MCP server was driven over stdio JSON-RPC (26 tools, errors still surface
the API's own message rather than being flattened), and the AppHost was run to
confirm both resources come up and Vite proxies /api through to the API.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S56bfZMGe1hnhpWP4CjjNw

src/Novelly.Api/Program.cs

@@ -0,0 +1,87 @@
+using System.Text.Json.Serialization;
+using Microsoft.AspNetCore.Diagnostics;
+using Microsoft.EntityFrameworkCore;
+using Novelly.Api.Agent;
+using Novelly.Api.Beats;
+using Novelly.Api.Chapters;
+using Novelly.Api.Characters;
+using Novelly.Api.Common;
+using Novelly.Api.Data;
+using Novelly.Api.Projects;
+using Novelly.Api.Scenes;
+using Novelly.Api.Tags;
+
+var builder = WebApplication.CreateBuilder(args);
+
+builder.AddServiceDefaults();
+builder.Services.AddNovelly(builder.Configuration);
+builder.Services.AddOpenApi();
+builder.Services.AddProblemDetails();
+
+// Enums travel as their names, so the React client and the MCP server both read
+// "Protagonist" rather than an ordinal that shifts whenever the enum is reordered.
+builder.Services.ConfigureHttpJsonOptions(options =>
+    options.SerializerOptions.Converters.Add(new JsonStringEnumConverter()));
+
+var corsOrigins = builder.Configuration.GetSection("Cors:Origins").Get<string[]>()
+    ?? ["http://localhost:5173"];
+
+builder.Services.AddCors(options => options.AddDefaultPolicy(policy => policy
+    .WithOrigins(corsOrigins)
+    .AllowAnyHeader()
+    .AllowAnyMethod()));
+
+var app = builder.Build();
+
+// Local-first tool: bring the SQLite file up to date on boot rather than making the
+// writer run a migration command before they can open the app.
+using (var scope = app.Services.CreateScope())
+{
+    await scope.ServiceProvider.GetRequiredService<NovelDbContext>().Database.MigrateAsync();
+}
+
+app.UseExceptionHandler(handler => handler.Run(async context =>
+{
+    var exception = context.Features.Get<IExceptionHandlerFeature>()?.Error;
+
+    var (status, title) = exception switch
+    {
+        NotFoundException => (StatusCodes.Status404NotFound, "Not found"),
+        AgentNotConfiguredException => (StatusCodes.Status503ServiceUnavailable, "Agent unavailable"),
+        ArgumentException or InvalidOperationException => (StatusCodes.Status400BadRequest, "Invalid request"),
+        _ => (StatusCodes.Status500InternalServerError, "Unexpected error")
+    };
+
+    if (status == StatusCodes.Status500InternalServerError)
+    {
+        app.Logger.LogError(exception, "Unhandled exception on {Path}", context.Request.Path);
+    }
+
+    await Results
+        .Problem(title: title, detail: exception?.Message, statusCode: status)
+        .ExecuteAsync(context);
+}));
+
+app.UseCors();
+
+if (app.Environment.IsDevelopment())
+{
+    app.MapOpenApi();
+}
+
+app.MapDefaultEndpoints();
+
+app.MapGet("/api/health", () => Results.Ok(new { status = "ok" })).WithTags("Health");
+
+app.MapProjectEndpoints()
+   .MapCharacterEndpoints()
+   .MapChapterEndpoints()
+   .MapBeatEndpoints()
+   .MapSceneEndpoints()
+   .MapTagEndpoints()
+   .MapAgentEndpoints();
+
+app.Run();
+
+/// <summary>Exposed so the tests can spin the API up with WebApplicationFactory.</summary>
+public partial class Program;