xcresult processor recovers on its own after Tailscale or NAT outages

The xcresult processor image is now resilient to Tailscale and NAT hiccups. During startup, tailscale up is bounded by a 60 second timeout, so a control-plane reachability issue fails the boot chain instead of hanging it, and launchd retries until things recover. As a consequence, processors that previously appeared Running/Ready while silently doing nothing now self-recover and resume draining the queue on their own, without needing a manual VM recycle.