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/Scenes/SceneDtos.cs

@@ -0,0 +1,62 @@
+using Novelly.Api.Common;
+
+namespace Novelly.Api.Scenes;
+
+public record SceneDto(
+    Guid Id,
+    Guid ChapterId,
+    int SortOrder,
+    string Title,
+    string? Summary,
+    string? Goal,
+    string? Conflict,
+    string? Outcome,
+    Guid? PovCharacterId,
+    string? PovCharacterName,
+    string? Location,
+    string? Prose,
+    int WordCount,
+    DraftStatus Status,
+    DateTimeOffset UpdatedAt);
+
+public record CreateSceneRequest(
+    string Title,
+    int? SortOrder = null,
+    string? Summary = null,
+    string? Goal = null,
+    string? Conflict = null,
+    string? Outcome = null,
+    Guid? PovCharacterId = null,
+    string? Location = null,
+    string? Prose = null,
+    DraftStatus Status = DraftStatus.Planned);
+
+public record UpdateSceneRequest(
+    string? Title = null,
+    int? SortOrder = null,
+    string? Summary = null,
+    string? Goal = null,
+    string? Conflict = null,
+    string? Outcome = null,
+    Guid? PovCharacterId = null,
+    string? Location = null,
+    string? Prose = null,
+    DraftStatus? Status = null);
+
+public static class SceneMapping
+{
+    public static SceneDto ToDto(this Scene s) => new(
+        s.Id, s.ChapterId, s.SortOrder, s.Title, s.Summary,
+        s.Goal, s.Conflict, s.Outcome,
+        s.PovCharacterId, s.PovCharacter?.Name, s.Location,
+        s.Prose, s.WordCount, s.Status, s.UpdatedAt);
+
+    /// <summary>
+    /// Whitespace-delimited word count. Good enough for progress tracking, and it costs
+    /// nothing to recompute on every save.
+    /// </summary>
+    public static int CountWords(string? prose) =>
+        string.IsNullOrWhiteSpace(prose)
+            ? 0
+            : prose.Split((char[]?)null, StringSplitOptions.RemoveEmptyEntries).Length;
+}