Windows Store updates reset Codex taskbar-corner / tray visibility preference

Summary

After a Microsoft Store update, Codex's Windows taskbar-corner / system-tray visibility preference is treated as a new app and the icon can return to the overflow menu, even when the user previously chose to keep it visible.

Reproduction

1. Install Codex Desktop from the Microsoft Store.
2. In Windows taskbar settings, configure Codex to remain visible in the taskbar corner.
3. Install a Codex update from the Microsoft Store.
4. Launch the updated app.
5. Observe that the tray icon may be placed back in the overflow menu and the preference must be set again.

Expected behavior

The user's taskbar-corner visibility choice should survive a normal Codex update.

Actual behavior

The update creates a new notification-area identity, so Windows does not reliably carry the previous visibility preference forward.

Evidence

The Microsoft Store install uses versioned MSIX package paths. Windows notification-area settings contain separate Codex records for distinct package versions, for example:

OpenAI.Codex_26.707.3748.0_x64__...\\app\\ChatGPT.exe
OpenAI.Codex_26.707.8168.0_x64__...\\app\\ChatGPT.exe

This strongly suggests that the tray identity presented to Windows changes across upgrades.

Suggested direction

Preserve a stable Windows tray identity across MSIX upgrades (for example, a stable AppUserModelID and/or tray icon GUID) so Windows can retain the user's existing notification-area preference.

Why this matters

This is a small but recurring update regression: users lose an explicit Windows preference after every app update. Fixing it proactively would avoid a common problem seen in comparable desktop coding apps.