Under the hood
Starting a background agent now disarms a startup watchdog that could otherwise flag it as stuck
What
When a background agent is kicked off, Claude Code now also calls disarmStartupWedgeWatchdog() on the server, in addition to the existing startup call that already ran.
Why
This prevents the startup watchdog (a mechanism that detects a process stuck, or "wedged", during startup) from misfiring against background agents as they start up.