Fedora: Fix Codex Locked-Out Apps

Symptom

When a previous Codex/GPT session wasn’t closed properly, the app can’t open.

Fix

rm ~/.config/Codex/SingletonLock

Removing the stale singleton lock file lets the app start again.

Open questions

• Why the lock isn’t released on crash — is there a cleaner recovery than rm?
• Does this apply to other Electron-style apps with SingletonLock?