Two docker-dev-only defects the Phase 6 live gate surfaced (both invisible to
`docker compose config`, which validates the file but never boots the app):
1. Driver-only site nodes crashed at boot with OptionsValidationException — LDAP
transport None + AllowInsecure false. Only central carried the Security__Ldap__*
block, but the site nodes serve OPC UA endpoints and validate LDAP options too, and
they override `environment` wholesale (YAML `<<:` doesn't deep-merge it). Extracted
the block to a shared &ldap-env anchor merged into every host node.
2. Site pairs split-brained at simultaneous startup (both nodes "JOINING itself",
250/250 instead of 250/240). Both are self-first seeds, so both run Akka's
FirstSeedNodeProcess; the partner didn't depend on its pair founder, so they raced
and each formed a 1-node cluster. Added an &akka-founder-healthcheck (bash /dev/tcp
probe of Akka 4053 — no nc/curl in the image) to site-a-1/site-b-1 and switched the
partners to depends_on service_healthy, so the founder forms first and the partner
JOINS it. (Carry the underlying simultaneous-cold-start property to Phase 7 — it is
inherent to symmetric self-first seeding, present for central since #459.)
Live gate record: docs/plans/2026-07-24-mesh-phase6-live-gate.md (legs 1-2 PASS —
three isolated meshes, one Primary per pair at 250/240).
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
Joseph Doherty