Adds resolve_lan_host(lan, topology) and partition_lans_by_host(h)
in topology.persistence — the single source of truth every per-host
caller (deployer, mutator, validator) consults to decide where a LAN
belongs. Resolution: lan.host_uuid → topology.target_host_uuid →
None (master).
Adds validator rule BRIDGE_HOST_SPLIT: a multi-homed (bridge) decky
attached to LANs that resolve to different hosts is rejected at
deploy-time. A bridge decky is one container with NICs into multiple
LANs; under the co-locate constraint (no overlay network), all those
LANs must share a host.
Adds decnet/topology/ with:
- config.TopologyConfig: pydantic model driving generation (depth,
branching_factor, deckies_per_lan_min/max, bridge_forward_probability,
cross_edge_probability, subnet_base_prefix, service selection, seed).
Emits GeneratedTopology dataclass (lans, deckies, edges).
- status.TopologyStatus + assert_transition: seven-state machine with
an explicit legal-transition table. torn_down is terminal; degraded
is schema-reserved for future Healer use.
- generator.generate: deterministic DAG generation under config.seed.
Builds a tree of LANs (DMZ at root), plants deckies in each LAN,
promotes one decky per non-DMZ LAN to a parent bridge, and rolls
cross-edges per cross_edge_probability for DAG shape.
- persistence: persist() writes a plan to the repo as pending;
transition_status() enforces state-machine legality; hydrate() loads
topology + children into a single dict.
Covered by tests/topology/{test_status,test_generator,test_persistence}.
