start-temps-cluster

# Start a local multi-node Temps cluster (Docker-in-Docker) Wraps `tools/dev-cluster/` — a docker-compose harness that runs a real Temps control plane plus 3 worker nodes, each a privileged DinD container, with the actual overlay network (VXLAN, `compute_cidr` allocation, cluster DNS) wired up exactly as it would be on real hardware. Use this whenever a fix or feature needs *more than one node* to prove anything — single-node `start-temps` cannot exercise cross-node scheduling, the overlay, or cluster DNS at all. ## Topology ``` ┌──── temps-underlay (10.42.0.0/24, docker bridge, the "VPC") ────┐ │ │ │ postgres 10.42.0.5 (TimescaleDB pg18, internal) │ │ control-plane 10.42.0.10 DinD + `temps serve` │ │ host ports 80 → 80, 443 → 443 (NOT 8080 — see Gotcha below) │ │ │ │ worker-1 10.42.0.21 worker-2 10.42.0.22 worker-3 10.42.0.23│ │ each: privileged DinD + `temps agent`, own dockerd │ └──────────────────────────────────────────────────────────────────┘ Allocator carves /24s from 172.20.0.0/16, one per worker: worker-1 → 172.20.0.0/24 worker-2 → 172.20.1.0/24 worker-3 → 172.20.2.0/24 Cross-node container traffic flows over a VXLAN tunnel pinned to the underlay IPs above. Within-node traffic uses the unchanged `temps-app-network` Docker bridge (same as single-node temps). ``` The te...