fixes microsoft/vscode-copilot#12412 (microsoft#250843)

Author: jrieken

src/vs/workbench/contrib/chat/browser/chatEditing/chatEditingCodeEditorIntegration.ts

@@ -339,7 +339,7 @@ export class ChatEditingCodeEditorIntegration implements IModifiedFileEntryEdito
 				// Note, this is a workaround for the `LineRange.isEmpty()` in diffEntry.original being `false` for newly inserted content
 				const isCreatedContent = decorations.length === 1 && decorations[0].range.isEmpty() && diffEntry.original.startLineNumber === 1;
 
-				if (!diffEntry.modified.isEmpty && !(isCreatedContent && (diffEntry.modified.endLineNumberExclusive - 1) === editorLineCount)) {
+				if (!diffEntry.modified.isEmpty) {
 					modifiedVisualDecorations.push({
 						range: diffEntry.modified.toInclusiveRange()!,
 						options: chatDiffWholeLineAddDecoration