Delete local files when DraftAttachment deleted

Packages/ComposeUI/Sources/ComposeUI/CoreData/DraftAttachment.swift

@@ -58,6 +58,13 @@ public final class DraftAttachment: NSManagedObject, Identifiable {
         case file(URL, UTType)
     }
     
+    public override func prepareForDeletion() {
+        super.prepareForDeletion()
+        if let fileURL {
+            try? FileManager.default.removeItem(at: fileURL)
+        }
+    }
+    
 }
 
 extension DraftAttachment {