Add track detail page with clickable cards

DeepDrftPublic.Client/ViewModels/TrackDetailViewModel.cs

@@ -0,0 +1,45 @@
+using DeepDrftModels.DTOs;
+using DeepDrftPublic.Client.Services;
+
+namespace DeepDrftPublic.Client.ViewModels;
+
+public class TrackDetailViewModel
+{
+    public ITrackDataService TrackData { get; }
+
+    public TrackDto? Track { get; set; }
+    public bool IsLoading { get; set; } = true;
+    public bool NotFound { get; set; }
+
+    public TrackDetailViewModel(ITrackDataService trackData)
+    {
+        TrackData = trackData;
+    }
+
+    public async Task Load(string entryKey)
+    {
+        // Idempotent across navigations: the scoped instance may be reused, so reset
+        // every flag before the fetch rather than relying on construction defaults.
+        IsLoading = true;
+        NotFound = false;
+        Track = null;
+
+        try
+        {
+            var result = await TrackData.GetTrack(entryKey);
+
+            if (result.Success && result.Value is not null)
+            {
+                Track = result.Value;
+            }
+            else
+            {
+                NotFound = true;
+            }
+        }
+        finally
+        {
+            IsLoading = false;
+        }
+    }
+}