Disabling userland-proxy makes rootless dockerd require br_netfilter
(/proc/sys/net/bridge/bridge-nf-call-iptables), absent in the rootless
netns on Debian -> default bridge creation fails -> daemon won't start.
Drop the daemon.json userland-proxy=false write. Source-IP is preserved
at L7 by Traefik (X-Forwarded-For), so no real loss.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Signed-off-by: librelad <librelad@digitalangels.vip>