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.

DeepDrftData/Repositories/TrackRepository.cs

@@ -0,0 +1,31 @@
+using Data.Data.Repositories;
+using Data.Errors;
+using DeepDrftData.Data;
+using DeepDrftModels.Entities;
+using Microsoft.Extensions.Logging;
+
+namespace DeepDrftData.Repositories;
+
+public class TrackRepository : Repository<DeepDrftContext, TrackEntity>
+{
+    public TrackRepository(
+        DeepDrftContext context,
+        ILogger<Repository<DeepDrftContext, TrackEntity>> logger,
+        IDbExceptionClassifier? classifier = null)
+        : base(context, logger, classifier: classifier)
+    {
+    }
+
+    protected override void UpdateEntity(TrackEntity target, TrackEntity source)
+    {
+        base.UpdateEntity(target, source); // copies CreatedAt, UpdatedAt, IsDeleted
+        target.EntryKey = source.EntryKey;
+        target.TrackName = source.TrackName;
+        target.Artist = source.Artist;
+        target.Album = source.Album;
+        target.Genre = source.Genre;
+        target.ReleaseDate = source.ReleaseDate;
+        target.ImagePath = source.ImagePath;
+        target.CreatedByUserId = source.CreatedByUserId;
+    }
+}