[BUG] Content area lags behind sidebar when switching between modules (Chat → Code)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

When switching between modules (e.g., from Chat to Code), the sidebar tabs switch
instantly, but the main content area has a noticeable delay before it updates to
the selected module's content.

This creates a jarring visual desync — the sidebar says "Code" but the content
area still shows the Chat view for a moment before catching up.

What Should Happen?

The sidebar and content area should switch simultaneously, or at least feel
visually synchronized. If content loading takes time, a loading skeleton or
placeholder should appear immediately rather than showing stale content from
the previous module.

Error Messages/Logs

Steps to Reproduce

1. Open Claude Desktop
2. Be in the Chat module
3. Click on the Code module in the sidebar
4. Observe: sidebar highlights Code immediately, but the content area

remains on Chat for a noticeable moment before switching

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

Claude 1.2773.0 (884b37)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Other

Additional Information

This may also occur when switching between other module combinations
(e.g., Cowork → Code, Code → Chat), but Chat → Code is the most noticeable.

Related issue: #48887 (font size and rendering concerns in Desktop modules)