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/TrackConverter.cs

@@ -0,0 +1,44 @@
+using DeepDrftModels.DTOs;
+using DeepDrftModels.Entities;
+using Models.Converters;
+
+namespace DeepDrftData;
+
+/// <summary>
+/// Static entity ↔ DTO converter consumed by the BlazorBlocks Manager base class.
+/// The DTO side mirrors the entity field-for-field; the audit columns
+/// (CreatedAt, UpdatedAt) come from BaseEntity / BaseModel.
+/// IsDeleted does not round-trip — soft-deleted rows are not exposed via the model.
+/// </summary>
+public class TrackConverter : IEntityToModelConverter<TrackEntity, TrackDto>
+{
+    public static TrackDto Convert(TrackEntity entity) => new()
+    {
+        Id = entity.Id,
+        CreatedAt = entity.CreatedAt,
+        UpdatedAt = entity.UpdatedAt,
+        EntryKey = entity.EntryKey,
+        TrackName = entity.TrackName,
+        Artist = entity.Artist,
+        Album = entity.Album,
+        Genre = entity.Genre,
+        ReleaseDate = entity.ReleaseDate,
+        ImagePath = entity.ImagePath,
+        CreatedByUserId = entity.CreatedByUserId
+    };
+
+    public static TrackEntity Convert(TrackDto model) => new()
+    {
+        Id = model.Id,
+        CreatedAt = model.CreatedAt,
+        UpdatedAt = model.UpdatedAt,
+        EntryKey = model.EntryKey,
+        TrackName = model.TrackName,
+        Artist = model.Artist,
+        Album = model.Album,
+        Genre = model.Genre,
+        ReleaseDate = model.ReleaseDate,
+        ImagePath = model.ImagePath,
+        CreatedByUserId = model.CreatedByUserId
+    };
+}