Desktop app sidebar account switcher looks visually broken and avatar falls back to initials

<img width="1126" height="382" alt="Image" src="https://github.com/user-attachments/assets/9dd8762c-a0e5-4c74-b7d3-97e0cebb9b8f" />

What happened?

In the Codex desktop app sidebar, the bottom account/profile switcher area looks visually inconsistent. It appears as a large gray translucent rectangle that spans the width of the sidebar and feels visually detached from the rest of the navigation.

The user avatar also appears to have fallen back to an initial ("H") instead of showing the account avatar/image.

Why this feels problematic

• The account switcher has much heavier contrast/background than the rest of the sidebar.
• The row height, padding, and background make it look like an accidental overlay or unfinished component.
• The avatar fallback makes the account identity feel degraded, especially for Plus users with a configured profile/avatar.

Expected behavior

• The bottom account switcher should match the sidebar's visual language and spacing.
• The user avatar should render the actual profile image when available, falling back to initials only when no avatar is available.
• If this is an intentional selected/active state, the styling should be more subtle and aligned with nearby items.

Screenshot

Attached screenshot shows the affected sidebar area.