At startup 'the broker is not reachable yet' is the normal case — a
container comes up in seconds, the overlay tunnel a moment later.
Exiting delegated the retry to the container runtime, which read as a
crash-loop to every restart-counting health check and every person
watching docker ps. Serve mode now retries with capped backoff, aloud,
indefinitely; a pinned-certificate mismatch still refuses at once, and
one-shot commands (emit, invoke, run) still fail fast.
jschoubben