Adds the `target_host_uuid` FK on `Topology` plus wiring through the
two create endpoints (`POST /topologies`, `POST /topologies/blank`).
Validates the mode/host pair: `mode='agent'` now requires a known,
routable host; `mode='unihost'` must leave the field unset.
Surfaced on `TopologySummary` so list/detail responses expose it.
Purely additive at the schema level — existing unihost flows unchanged
(field defaults to `NULL`).
Step 1 of the agent <-> topology integration.
UI-created deckies (api_decky_crud, api_create_blank_topology) write
decky_config as sent by the client — typically just archetype flags,
without the name/ips_by_lan fields compose.py requires. The generator
path populates them at persist() time, so compose worked for generated
topologies but KeyError'd on UI-created ones.
Normalise in hydrate() so every write path feeds the same shape
downstream: mirror decky.name into decky_config.name, and allocate
per-LAN IPs deterministically (reserving the primary decky.ip where it
falls in-subnet, then filling remaining edges with next_free).
MazeNET phase 2 step 5. Pure storage — the generator emits None for
x/y and the web canvas fills them in later. No logic changes; no
compose, deploy, or validator impact.
MazeNET phase 2 step 2. Mirrors the flat-fleet service_config pattern
(DeckyConfig.service_config → composer → svc.compose_fragment) into the
topology compose pipeline, so a hand-authored decky can carry overrides
like {"ssh": {"password": "megapassword"}} and the ssh fragment reads
them just like the flat path does.
- _PlannedDecky gains service_config: dict[str, dict].
- persist() stores it under decky_config["service_config"].
- topology/compose.py passes cfg.get("service_config", {}).get(svc, {})
to svc.compose_fragment(service_cfg=...).
Schema unchanged — service_config lives inside the existing
decky_config JSON blob. Zero changes in decnet/services/*.
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}.
