[FEATURE] Tab-based layout for active threads in Codex macOS app

What feature would you like to see?

Tab-based layout for managing currently active threads in the Codex macOS app, instead of (or in addition to) the current left sidebar navigation.

Problem: My muscle memory is trained on terminal-based Codex sessions where I manage multiple sessions via terminal tabs. The left sidebar paradigm in the macOS app breaks this workflow — I instinctively reach for tab-switching shortcuts rather than clicking a sidebar item.

Proposed solution: Add a tab bar (similar to browser/terminal tab bars) along the top of the window for switching between active threads. This would let users who come from the CLI experience navigate threads the same way they navigate terminal tabs.

<img width="500" src="https://github.com/user-attachments/assets/1f78a13d-60b6-4840-b32e-982b8bf34456"/>

Additional information

Note: I'm not sure if this is the best communication channel for Codex macOS app feature requests. If it isn't, could you point me to where I should post feature requests for the desktop app?

• Codex CLI version: codex-cli 0.98.0
• Platform: macOS (macOS v26.2, arm64)