Two-node primary/secondary architecture with per-service replication:
ZFS send/recv 15min for volumes, postgres streaming replication for
DBs, Redis Sentinel, Tailscale mesh. Phased plan from cobblestone
intake to eventual K3s/Nomad cluster at 3+ nodes. Service placement
table, failure-scenario RTO/RPO matrix, open decisions documented.
STATE.md = source-of-truth for current state + pending decisions.
Append to changelog when state changes. Don't rewrite history.
COBBLESTONE-INTAKE.md = template the operator fills before agent A2
runs the cobblestone audit. Captures network/SSH/hardware/OS/docker
state + operator-driven migration decisions (LUKS, DE, userns-remap,
RC revive-or-retire, Headscale SPOF, cockpit).
