Use <folder-name>.worktrees/pr-<number> as default worktree path

Agent-Logs-Url: https://github.com/microsoft/vscode-pull-request-github/sessions/280f22ec-34a1-44b7-a2e9-4d3e5f750748

Co-authored-by: alexr00 <38270282+alexr00@users.noreply.github.com>

Author: Copilot

src/github/worktree.ts

@@ -44,7 +44,8 @@ export async function checkoutPRInWorktree(
 	// Prepare for operations
 	const repoRootPath = repositoryToUse.rootUri.fsPath;
 	const parentDir = path.dirname(repoRootPath);
-	const defaultWorktreePath = path.join(parentDir, `pr-${pullRequestModel.number}`);
+	const repoFolderName = path.basename(repoRootPath);
+	const defaultWorktreePath = path.join(parentDir, `${repoFolderName}.worktrees`, `pr-${pullRequestModel.number}`);
 	const branchName = prHead.ref;
 	const remoteName = pullRequestModel.remote.remoteName;