Implement RemoveImageAsync method in ModifiableImagesCollection

Implement the `RemoveImageAsync` method in `ModifiableImagesCollection`.

* **Method Implementation**
  - Find the image in the collection by its ID.
  - Throw an `ArgumentException` if the image is not found.
  - Use `Client.Dag.PutAsync` to update the image and key CIDs.
  - Create a `ValueUpdateEvent` for the image removal.
  - Apply the entry update and append the new entry.
  - Update the `EventStreamPosition`.

---

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Author: Arlodotexe

src/Nomad/ModifiableImagesCollection.cs

@@ -1,4 +1,4 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
 using System.Linq;
 using CommunityToolkit.Diagnostics;
 using Ipfs;
@@ -50,9 +50,23 @@ public async Task AddImageAsync(IFile imageFile, CancellationToken cancellationT
     }
 
     /// <inheritdoc />
-    public Task RemoveImageAsync(IFile imageFile, CancellationToken cancellationToken)
+    public async Task RemoveImageAsync(IFile imageFile, CancellationToken cancellationToken)
     {
-        throw new NotImplementedException();
+        var image = Inner.Inner.Images.FirstOrDefault(img => img.Id == imageFile.Id);
+        if (image == null)
+        {
+            throw new ArgumentException("Image not found in the collection.", nameof(imageFile));
+        }
+
+        var keyCid = await Client.Dag.PutAsync(image.Id, pin: KuboOptions.ShouldPin, cancel: cancellationToken);
+        var valueCid = await Client.Dag.PutAsync(image, pin: KuboOptions.ShouldPin, cancel: cancellationToken);
+
+        var updateEvent = new ValueUpdateEvent(Id, nameof(RemoveImageAsync), (DagCid)keyCid, (DagCid)valueCid, true);
+
+        await ApplyEntryUpdateAsync(updateEvent, image, cancellationToken);
+        var appendedEntry = await AppendNewEntryAsync(updateEvent, cancellationToken);
+
+        EventStreamPosition = appendedEntry;
     }
 
     /// <inheritdoc />
@@ -134,4 +148,4 @@ public override Task ResetEventStreamPositionAsync(CancellationToken cancellatio
 
         return Task.CompletedTask;
     }
-}
+}