Codex Desktop Windows visual regression: main panel lost rounded corner after update

What version of the Codex App are you using (From “About Codex” dialog)?

Codex App version: 26.623.4041.0

What subscription do you have?

Pro

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What issue are you seeing?

After the recent Codex Desktop update, the main panel on Windows lost its previous rounded / smooth top-left corner transition.

The corner between the left sidebar and the main workspace now renders as a sharp square edge. Previously this area had a smooth rounded transition, consistent with the rest of the Codex UI. The new sharp corner looks visually broken and inconsistent with the app's rounded design language.

<img width="371" height="197" alt="Image" src="https://github.com/user-attachments/assets/a46ab2fe-d240-49e2-93b3-43260e49676e" />

What steps can reproduce the bug?

Open Codex Desktop on Windows

What is the expected behavior?

The main workspace panel should keep the previous rounded / smooth corner transition, matching the rest of the Codex Desktop UI

Additional information

_No response_