feat(data): rename *.Services projects, lift TrackEntity onto BlazorBlocks data layer, regenerate initial Postgres migration

DeepDrftWeb.Services → DeepDrftData; DeepDrftContent.Services → DeepDrftContent.Data.
TrackEntity:BaseEntity, TrackRepository:Repository<>, TrackManager:Manager<>+ITrackService.
Drops DeepDrftModels PagingParameters/PagedResult in favour of Models.Common.* from BlazorBlocks.
InitialCreate migration captures full schema including is_deleted index.

DeepDrftWeb/Controllers/CmsUploadController.cs

@@ -1,7 +1,7 @@
 using System.Net.Http.Headers;
 using System.Security.Claims;
+using DeepDrftData;
 using DeepDrftModels.Entities;
-using DeepDrftWeb.Services;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
 
@@ -10,7 +10,7 @@ namespace DeepDrftWeb.Controllers;
 /// <summary>
 /// CMS upload surface. Proxies a WAV + metadata multipart form to DeepDrftContent's
 /// POST api/track/upload, then persists the returned unpersisted TrackEntity to SQL via
-/// ITrackService.Create. DeepDrftWeb intentionally does not reference DeepDrftContent.Services
+/// ITrackService.Create. DeepDrftWeb intentionally does not reference DeepDrftContent.Data
 /// (CMS-PLAN §5, Option B) — all vault access is over HTTP.
 /// </summary>
 [ApiController]