Circle's arc-execution/arc-consensus images are distroless with only the `arc` user and no `root` entry in /etc/passwd, so `user: root` failed with "unable to find user root". Run by numeric uid 0:0 instead (no passwd lookup needed; root can write the root-owned named volumes). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>