Wire NowPlayingStats to live aggregates: add SQL track duration column, stats endpoint, and duration backfill

DeepDrftModels/DTOs/HomeStatsDto.cs

@@ -0,0 +1,37 @@
+using DeepDrftModels.Enums;
+
+namespace DeepDrftModels.DTOs;
+
+/// <summary>
+/// Aggregate figures behind the public home hero stat row (NowPlayingStats). A single read returns
+/// everything the three cards need so the client makes one round-trip. All counts exclude soft-deleted
+/// rows. The Plays card is a static placeholder and has no field here.
+/// </summary>
+public class HomeStatsDto
+{
+    /// <summary>Total non-deleted tracks whose release is the Cut medium. The Studio Cuts card's primary figure.</summary>
+    public int CutTrackCount { get; set; }
+
+    /// <summary>
+    /// Per-ReleaseType counts of non-deleted Cut releases. Only types with at least one release are
+    /// present — a zero-count type is absent from the list (the card suppresses it). The Studio Cuts
+    /// card's secondary breakdown.
+    /// </summary>
+    public List<CutReleaseTypeCount> CutReleaseTypeCounts { get; set; } = [];
+
+    /// <summary>Total non-deleted releases of the Mix medium. The Mixes card's primary figure ("N Sets").</summary>
+    public int MixReleaseCount { get; set; }
+
+    /// <summary>
+    /// Sum of DurationSeconds across all non-deleted tracks on Mix releases. Tracks with a null
+    /// duration (not yet backfilled) contribute 0. The Mixes card's secondary figure, rendered hh:mm.
+    /// </summary>
+    public double MixRuntimeSeconds { get; set; }
+}
+
+/// <summary>One row of the Cut release-type breakdown: a ReleaseType and how many Cut releases have it.</summary>
+public class CutReleaseTypeCount
+{
+    public ReleaseType ReleaseType { get; set; }
+    public int Count { get; set; }
+}

DeepDrftModels/DTOs/TrackDto.cs

@@ -16,6 +16,7 @@ public class TrackDto : BaseModel
     public string TrackName { get; set; } = string.Empty;
     public string? OriginalFileName { get; set; }
     public int TrackNumber { get; set; } = 1;
+    public double? DurationSeconds { get; set; }
     public long? ReleaseId { get; set; }
     public ReleaseDto? Release { get; set; }
 }