Notify on image-property changes in ResultViewModel

The Image, BadgeImage, and PreviewImage setters never raised
PropertyChanged, even though the LoadImageAsync comments asserted that
"modifying the property" was supposed to trigger the event. The notify
call was lost in 2021 when the LazyAsync<ImageSource> wrapper was
inlined (e8691c2).

The bug usually hides because subsequent identical IcoPath lookups hit
ImageCache synchronously in the getter, so the binding sees the loaded
image on its first evaluation. But when a brand-new IcoPath comes in
and the host doesn't virtualize the row out and back in (e.g., a
single-result query like a chat plugin's "Ask" preview), the field is
mutated post-await and the binding stays on LoadingImage forever.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: TrueCrimeDev

Flow.Launcher/ViewModel/ResultViewModel.cs

@@ -175,7 +175,11 @@ public ImageSource Image
 
                 return _image;
             }
-            private set => _image = value;
+            private set
+            {
+                _image = value;
+                OnPropertyChanged();
+            }
         }
 
         public ImageSource BadgeImage
@@ -190,7 +194,11 @@ public ImageSource BadgeImage
 
                 return _badgeImage;
             }
-            private set => _badgeImage = value;
+            private set
+            {
+                _badgeImage = value;
+                OnPropertyChanged();
+            }
         }
 
         public ImageSource PreviewImage
@@ -205,7 +213,11 @@ public ImageSource PreviewImage
 
                 return _previewImage;
             }
-            private set => _previewImage = value;
+            private set
+            {
+                _previewImage = value;
+                OnPropertyChanged();
+            }
         }
 
         /// <summary>