refactor(AnnotationParams): AnnotationJSObject aktualisieren, um IAnnotation (anstelle von Annotation) zu enthalten

- Hintergrund in AnnotationJSObject hinzufügen, wenn er nicht null ist

EnvelopeGenerator.Web/Models/Annotation/AnnotationParams.cs

@@ -6,11 +6,12 @@ public class AnnotationParams
 {
     public AnnotationParams()
     {
-        _AnnotationJSObjectInitor = new(() => _annots.ToDictionary(a => a.Name.ToLower(), a => a));
+        _AnnotationJSObjectInitor = new(CreateAnnotationJSObject);
     }
 
     public Background? Background { get; init; }
 
+    #region Annotation
     [JsonIgnore]
     public Annotation? DefaultAnnotation { get; init; }
 
@@ -55,8 +56,21 @@ public class AnnotationParams
             }
         }
     }
+    #endregion
 
-    private readonly Lazy<Dictionary<string, Annotation>> _AnnotationJSObjectInitor;
+    #region AnnotationJSObject
+    private Dictionary<string, IAnnotation> CreateAnnotationJSObject()
+    {
+        var dict = _annots.ToDictionary(a => a.Name.ToLower(), a => a as IAnnotation);
 
-    public Dictionary<string, Annotation> AnnotationJSObject => _AnnotationJSObjectInitor.Value;
+        if (Background is not null)
+            dict.Add(Background.Name.ToLower(), Background);
+
+        return dict;
+    }
+
+    private readonly Lazy<Dictionary<string, IAnnotation>> _AnnotationJSObjectInitor;
+
+    public Dictionary<string, IAnnotation> AnnotationJSObject => _AnnotationJSObjectInitor.Value;
+    #endregion
 }