Thread rename may not sync across multiple open VS Code windows

[Just-Boring-Cat]

Summary

When multiple VS Code windows are open at the same time, renaming a Codex thread in one window may not update the same thread title in other open windows/sessions.

This appears to be a multi-window state synchronization issue. One window updates the title correctly, but another already-open window can continue showing stale data (and may later overwrite persisted cache/state on shutdown/reload).

Repro Steps

1. Open VS Code window A with the OpenAI ChatGPT/Codex extension.
2. Open VS Code window B (same machine, same user profile) with the OpenAI ChatGPT/Codex extension.
3. Ensure both windows have access to Codex threads and the patch is applied.
4. In window A, rename a thread using Rename Codex Thread (Command Palette or right-click menu).
5. Observe the renamed thread in window A updates immediately.
6. Switch to window B and inspect the same thread.

Actual Behavior

• Window B may still show the old thread title.
• Depending on reload/restart timing, stale in-memory state from another window may overwrite the updated title/cache.

Expected Behavior

• Thread renames should propagate to all open VS Code windows using the same profile/session.
• At minimum, other windows should refresh the thread title when the thread list is reopened or when a thread becomes active.

Suspected Cause

• The extension/webview title cache is maintained in-memory per VS Code window.
• Rename updates are applied in the active window runtime, but other windows do not receive a live sync event.
• On shutdown/reload, another window may flush stale thread-title cache back to disk.

Impact

• Confusing UX when working with multiple projects/windows.
• Renames can appear flaky or "revert" unexpectedly.
• Harder to trust the rename feature in multi-window workflows.

Possible Fix Directions

• Broadcast thread-title updates to all open extension hosts/windows (if possible through extension host state or shared event channel).
• Rehydrate/reconcile thread titles from backend persistent state before writing caches.
• Add conflict-safe cache writes (avoid overwriting newer timestamps/versions).
• Refresh titles when opening the thread list or on window focus.

Environment (example)

• VS Code: multiple windows open
• OpenAI extension: stable (release) build with patch applied
• OS: macOS