macOS desktop upgrade can strand existing local tasks on stale symlinked writable roots

Summary

After updating and restarting the macOS Codex/ChatGPT desktop app, an existing local Codex task can fail before startup because sandbox setup rejects a persisted writable root that is now a symlink.

Error

failed to load AGENTS.md instructions for environment `local`: failed to prepare fs sandbox: failed to prepare Seatbelt sandbox: writable root <legacy-root> contains symlink component <legacy-root>; symlinked writable roots are not supported

Context

• Platform: macOS
• Trigger: update to the latest desktop app version, then restart.
• The task's actual current folder already uses the resolved, non-symlink path.
• A legacy compatibility path remains as a symlink to that location.
• The task UI exposes no Environment or Writable folders control, so the persisted root cannot be inspected, changed, or removed.

Expected behavior

The upgrade should either canonicalize persisted symlinked writable roots to their resolved paths, or preserve the existing task's ability to start and provide a user-visible repair path.

Actual behavior

The task fails before it can load AGENTS.md or run any work. Restarting does not help, and there is no in-app way to repair the stale root.

Requested fix

Please add migration/canonicalization for persisted writable roots and an in-app recovery path for unsupported stale roots.

Start by tracing task startup through persisted writable-root loading and macOS Seatbelt sandbox preparation, using the reported symlinked legacy path as the reproduction case. Check where the existing task fails before AGENTS.md loads; done means upgrade migration or recovery lets the task start with a resolved writable root and provides an in-app repair path.