fix: adding extension hack

fix

backend/agents/client/chat.go

@@ -216,6 +216,12 @@ func (chat *Chat) AddImage(imageName string, image []byte, query *string) error
 		index += 1
 	}
 
+	if len(extension) == 0 {
+		// Hacky! It seems apple doesnt add extension.
+		// BIG TODO: take better metadata from the image.
+		extension = "png"
+	}
+
 	messageContent.Content[index] = ImageMessageContent{
 		ImageType: "image_url",
 		ImageUrl: ImageMessageUrl{