fix: review remediation — _busy finally block, TrackNotFoundMessage const, null-safe error log

DeepDrftContent/Controllers/TrackController.cs

@@ -251,7 +251,7 @@ public class TrackController : ControllerBase
         }
 
         var error = result.Messages.FirstOrDefault()?.Message ?? "Unknown error";
-        if (string.Equals(error, "Track not found.", StringComparison.Ordinal))
+        if (string.Equals(error, UnifiedTrackService.TrackNotFoundMessage, StringComparison.Ordinal))
         {
             return NotFound();
         }

DeepDrftContent/Services/UnifiedTrackService.cs

@@ -14,6 +14,7 @@ namespace DeepDrftContent.Services;
 /// </summary>
 public class UnifiedTrackService
 {
+    internal const string TrackNotFoundMessage = "Track not found.";
     private readonly ContentTrackService _contentTrackService;
     private readonly ITrackService _sqlTrackService;
     private readonly FileDb _fileDatabase;
@@ -89,7 +90,7 @@ public class UnifiedTrackService
 
         if (lookup.Value is null)
         {
-            return Result.CreateFailResult("Track not found.");
+            return Result.CreateFailResult(TrackNotFoundMessage);
         }
 
         var entryKey = lookup.Value.EntryKey;
@@ -97,7 +98,7 @@ public class UnifiedTrackService
         var sqlDelete = await _sqlTrackService.Delete(id);
         if (!sqlDelete.Success)
         {
-            var error = sqlDelete.Messages.FirstOrDefault()?.Message;
+            var error = sqlDelete.Messages.FirstOrDefault()?.Message ?? "unknown error";
             _logger.LogError("DeleteAsync: SQL delete failed for track {TrackId}: {Error}", id, error);
             return Result.CreateFailResult("Failed to delete track.");
         }

DeepDrftManager/Components/Pages/Tracks/TrackEdit.razor

@@ -178,13 +178,15 @@
             {
                 var error = result.Messages.FirstOrDefault()?.Message ?? "Unknown error";
                 Snackbar.Add($"Delete failed: {error}", Severity.Error);
-                _busy = false;
             }
         }
         catch (Exception ex)
         {
             Logger.LogError(ex, "Delete failed for track {TrackId}", Id);
             Snackbar.Add("Delete failed — please try again.", Severity.Error);
+        }
+        finally
+        {
             _busy = false;
         }
     }