Desktop sidecar spawn can time out on macOS with interactive shell startup

[ysm-dev]

What happens

Running bun dev:desktop can fail with Failed to spawn OpenCode Server (Health check timed out) on some macOS environments.

Reproduction

1. Run bun dev:desktop
2. Desktop spawns sidecar through /bin/zsh -il -c ...
3. Sidecar health check times out after 30s

Notes

• On the same machine, SHELL=/bin/sh bun dev:desktop starts successfully.
• This suggests interactive shell startup hooks can delay sidecar startup enough to miss the health-check window.