nx_ha_failover.nx

nx_ha_failover.nx -- CAP-HA-FAILOVER: multi-node failover to KILL THE SPOF (the single NAS the stability census flagged as our AWS-gap). Deterministic failover state machine over two nodes' health: primary down + standby up -> promote standby; both down -> DEGRADED (honest, never a false "up"); recover to the primary when it returns. Conservative (fail back only when the current active is down) -> no flapping. Pure integer, gateable offline; composes the true-health verdict (mc_verdict UP/DOWN). The DATA-PLANE replication + a real standby host are the infra rungs this logic drives. license_tier: ORIGINAL