Strip AI warning suffix from "Apply Suggestion Using AI" chat input (#8611)

* Initial plan

* Initial plan for fixing AI warning suffix in applySuggestionWithCopilot

Co-authored-by: alexr00 <38270282+alexr00@users.noreply.github.com>
Agent-Logs-Url: https://github.com/microsoft/vscode-pull-request-github/sessions/a47a6887-194e-4dd7-966a-3459c61cc24c

* Fix: Use rawComment.body in applySuggestionWithCopilot to exclude AI warning suffix

When applying a suggestion using AI for Copilot Code Review comments,
the rendered comment body included the "Copilot is powered by AI, so
mistakes are possible" suffix. Use rawComment.body instead to get the
original comment text without the display-only warning.

Co-authored-by: alexr00 <38270282+alexr00@users.noreply.github.com>
Agent-Logs-Url: https://github.com/microsoft/vscode-pull-request-github/sessions/a47a6887-194e-4dd7-966a-3459c61cc24c

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: alexr00 <38270282+alexr00@users.noreply.github.com>

Author: Copilot

src/commands.ts

@@ -1848,9 +1848,10 @@ ${contents}
 
 			const isThread = GHPRCommentThread.is(comment);
 			const commentThread = isThread ? comment : comment.parent;
-			const commentBody = isThread ? comment.comments[0].body : comment.body;
+			const firstComment = isThread ? comment.comments[0] : comment;
 			commentThread.collapsibleState = vscode.CommentThreadCollapsibleState.Collapsed;
-			const message = commentBody instanceof vscode.MarkdownString ? commentBody.value : commentBody;
+			const message = firstComment instanceof GHPRComment ? firstComment.rawComment.body
+				: (firstComment.body instanceof vscode.MarkdownString ? firstComment.body.value : firstComment.body);
 
 			if (isThread) {
 				// For threads, open the Chat view instead of inline chat