[BUG] Desktop app Code tab: session never returns first response on MacBook Pro M5 (unhealthy cycle 30s, no_response, no process crash)

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?

In the Code tab of the Claude Desktop app, every session starts correctly but never produces a first response. After sending any prompt (even a simple "bonjour" in a brand-new empty local folder), the message is received (the session title is auto-set from the prompt), but no response, no thinking indicator, and no error ever appears. The session spins indefinitely and is marked unhealthy after 30 seconds.
Crucially, the underlying Claude Code process does not crash. The log shows query iterator completed followed by unhealthy cycle (30s, hadFirstResponse=false, reason=no_response). There is no Claude Code process exited with code 1. This distinguishes it from the several existing reports where the process exits at 0s (e.g. #59866, #46161, #37641). Here the process stays alive but never streams a first response.
The Claude Code CLI works perfectly on the same machine, same account, same project folders.

What Should Happen?

The Code tab session should stream a first response like the CLI does.

Error Messages/Logs

[info] Starting local session local_xxx in /Users/<user>/dev-local/test-cc
[info] [CCD] Passing 1 plugin(s) to SDK (skills: 1, remote: 0, local: 0)
[info] Using Claude Code binary at: /Users/<user>/Library/Application Support/Claude/claude-code/2.1.146/claude.app/Contents/MacOS/claude
[info] LocalSessions.updateSession: options={"title":"Bonjour","titleSource":"auto"}
[info] [IdleManager:session] Starting idle timeout
[info] Session local_xxx query iterator completed
[info] [CCD CycleHealth] unhealthy cycle for local_xxx (30s, hadFirstResponse=false, reason=no_response)

Steps to Reproduce

Open the Desktop app, Code tab, Local mode
Select any local folder (reproduced even with a brand-new empty folder outside any cloud-synced path)
Send any prompt
Message is received, session title set, but no response ever streams; after 30s the session is marked unhealthy

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.36

Claude Code Version

2.1.146

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_