Improved several small things (#602)

app/MindWork AI Studio/Chat/ContentImage.cs

@@ -1,6 +1,7 @@
 using System.Text.Json.Serialization;
 
 using AIStudio.Provider;
+using AIStudio.Tools.Validation;
 
 namespace AIStudio.Chat;
 
@@ -50,6 +51,23 @@ public sealed class ContentImage : IContent, IImageSource
 
     #endregion
 
+    /// <summary>
+    /// Creates a ContentImage from a local file path.
+    /// </summary>
+    /// <param name="filePath">The path to the image file.</param>
+    /// <returns>A new ContentImage instance if the file is valid, null otherwise.</returns>
+    public static async Task<ContentImage?> CreateFromFileAsync(string filePath)
+    {
+        if (!await FileExtensionValidation.IsImageExtensionValidWithNotifyAsync(filePath))
+            return null;
+
+        return new ContentImage
+        {
+            SourceType = ContentImageSource.LOCAL_PATH,
+            Source = filePath,
+        };
+    }
+
     /// <summary>
     /// The type of the image source.
     /// </summary>