Desktop app Code mode completely broken - "API Error: Rate limit reached" / "Failed to load session"

Description

The desktop app's Code tab is completely non-functional. Every new session immediately fails with either "API Error: Rate limit reached" or "Failed to load session." This has been happening for multiple days.

• Chat mode works perfectly on the same account
• CLI (claude) works perfectly on the same machine
• Only the desktop Code tab is broken

Environment

• App version: 1.1.5749
• OS: macOS (Apple Silicon, Darwin 25.3.0)
• Plan: Max
• CLI version: Working fine in parallel

Steps to reproduce

1. Open Claude desktop app
2. Click "Code" tab
3. Start a new session
4. Send any message (e.g., "hi")
5. Immediately get "API Error: Rate limit reached" or blank screen with no response

What I've tried (none of these fix it)

• Killing all Claude processes
• Disabling all extensions
• Clearing all caches, sessions, cookies, and app data
• Complete uninstall + fresh reinstall (deleted app + all Application Support data)
• Fresh login after reinstall
• Switching models (Opus 4.6, Sonnet 4.6)
• Multiple new sessions across different projects

Logs

The desktop log (~/Library/Logs/Claude/claude.ai-web.log) shows:

[error] [REACT_QUERY_CLIENT] QueryClient error: Error: ["account_profile"] data is undefined
[error] [REACT_QUERY_CLIENT] QueryClient error: TypeError: Failed to fetch (claude.ai)
[warn] [LOCAL_SESSION] [RenderLoopDetector] Rapid re-rendering in CCSessionList: 20 renders in 1000ms
[error] Uncaught Error: Minified React error #418

Earlier logs also showed hundreds of rate_limit_event and queue-operation messages per second in a retry loop.

Impact

Code mode has been completely unusable for days. Chat mode and CLI work fine, confirming this is specific to the Code tab's server-side integration.