MacOS desktop app keeps undeletable "ghost" conversations in the sidebar after deletion

Environment

• App: ChatGPT macOS desktop app (Codex-based), version 26.825.51511 (latest)
• OS: macOS (Apple Silicon)
• Account: fengw2002@gmail.com (Plus)

Description
After deleting several conversations, their titles remain stuck in the desktop app's sidebar "Recent" list. These ghost entries:

1. Show "Unable to load this ChatGPT conversation" when clicked;
2. Fail with "Chat could not be deleted" when using right-click → Delete chat;
3. Fail with "Conversation could not be archived" when using Archive;
4. Redirect to the chatgpt.com homepage when opened via "Open on chatgpt.com" — the conversation no longer exists server-side (e.g. conversation ID: 6a915541-a670-83ea-a3a1-baea4345992d);
5. Do NOT appear in the web sidebar, so the issue is specific to the desktop app's conversation list index.

Troubleshooting already attempted (none worked)

1. Fully quitting and relaunching the app;
2. Deleting local app data and caches (~/Library/Application Support/com.openai.codex, ~/Library/Caches/com.openai.codex) — the list was restored identically after relaunch;
3. Signing out and signing back in — ghost entries persist and delete/archive still fail;
4. Confirmed the app is on the latest version.

Conclusion
The conversation objects were deleted server-side, but the desktop app's conversation list index retains stale references. Delete/archive requests fail because the target no longer exists, so the list cannot self-heal. The state is account-bound (server-side), independent of device or local data.

Request
Please purge the stale entries from my account's desktop conversation list, or fix the sync bug where deleting a non-existent conversation leaves a permanent sidebar entry.

No source file or test is identified in the report. Start by tracing desktop conversation-list synchronization and deletion handling for server-missing conversation IDs; done means stale entries are removed and deletion or archive requests no longer leave them behind, with a regression test.