fix: handle linked-worktree .git layout and render no-op keep as success

- Use `git rev-parse --git-dir` instead of hardcoded `.git/` path for
  the exclude file, fixing ENOTDIR when repo is a linked worktree.
- Render no-op keep cleanup as success instead of misleading "failed"
  message when there were simply no changes to apply.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: peterdrier

plugins/codex/scripts/lib/git.mjs

@@ -192,8 +192,10 @@ export function createWorktree(repoRoot) {
   const worktreesDir = path.join(repoRoot, ".worktrees");
   fs.mkdirSync(worktreesDir, { recursive: true });
 
-  // Ensure .worktrees/ is excluded from the target repo without modifying tracked files
-  const excludePath = path.join(repoRoot, ".git", "info", "exclude");
+  // Ensure .worktrees/ is excluded from the target repo without modifying tracked files.
+  // Use git rev-parse to resolve the real git dir (handles linked worktrees where .git is a file).
+  const gitDir = gitChecked(repoRoot, ["rev-parse", "--git-dir"]).stdout.trim();
+  const excludePath = path.join(gitDir, "info", "exclude");
   const excludeContent = fs.existsSync(excludePath) ? fs.readFileSync(excludePath, "utf8") : "";
   if (!excludeContent.includes(".worktrees")) {
     fs.mkdirSync(path.dirname(excludePath), { recursive: true });

plugins/codex/scripts/lib/render.mjs

@@ -490,6 +490,8 @@ export function renderWorktreeCleanupResult(action, result, session) {
   if (action === "keep") {
     if (result.applied) {
       lines.push(`Applied changes from \`${session.branch}\` and cleaned up.`);
+    } else if (result.detail === "No changes to apply.") {
+      lines.push(`No changes to apply. Worktree and branch \`${session.branch}\` cleaned up.`);
     } else {
       lines.push(`Failed to apply changes: ${result.detail}`);
       lines.push("");