When a non-DMZ LAN is created via POST /lans, look up the topology's
gateway (decky with forwards_l3=True attached to the DMZ) and insert
an edge binding it to the new LAN. The gateway becomes multi-homed
to every internal LAN automatically, so DMZ_ORPHAN cannot arise
from ordinary editor use.
Also fixes delete_lan: the home-decky guard used scalar_one_or_none,
which blew up when the gateway already had >1 'other' LAN edge.
Switch to scalars().first() — we only need to know *some* other
edge exists, not a unique one.
POST /topologies/blank seeded the gateway decky with
archetype=host-gateway + network_mode=host, but neither was wired:
no compose writer reads network_mode and host-gateway is not a real
archetype. Replace with archetype=deaddeck + forwards_l3=true so the
gateway is a normal multi-homed bridge decky, consistent with how
compose.py interprets forwards_l3 (sysctl + NET_ADMIN).
Edge marked is_bridge=true, forwards_l3=true so downstream readers
(generator, compose, validator) see a real bridge attachment.
DECNET's app-level RequestValidationError handler remaps structural
422→400, including query/path constraint violations (limit bounds,
the next-subnet base pattern, etc.). Schemathesis fuzzing will drive
those code paths and fail response_schema_conformance unless 400 is
declared in responses={}. Adds the entry to every phase-3 read route.
GET /api/v1/topologies — paginated list with status filter. Extends
repo.list_topologies() to accept limit/offset and adds count_topologies()
for the total envelope field.
GET /api/v1/topologies/{id} — hydrated TopologyDetail; 404 if missing.
GET /api/v1/topologies/{id}/status-events — audit trail, limit-capped.
Catalog helpers for the phase-4 canvas UI:
* GET /topologies/services — full service catalog.
* GET /topologies/next-subnet?base=172.20 — wraps SubnetAllocator against
reserved_subnets across non-torn-down topologies.
* GET /topologies/{id}/lans/{lan_id}/next-ip — IPAllocator pre-seeded
with existing decky IPs in that LAN.
All read routes are viewer-or-admin. Sub-routers are included in an
order that keeps literal catalog paths (/services, /next-subnet) from
being shadowed by the /{topology_id} trie branch.
Add Pydantic DTOs in decnet/web/db/models.py covering every phase-3
endpoint shape: TopologyGenerateRequest, TopologySummary/Detail, child
create/update requests, MutationEnqueueRequest (Literal op guard),
MutationRow with JSON-payload decoder, validation/version/not-editable
error envelopes, and the three catalog responses.
Create decnet/web/router/topology/ as an import-safe package exporting
topology_router (prefix /topologies) — sub-routers land step-by-step in
subsequent commits. Mount under the main api router alongside swarm_mgmt.
tests/api/topology/test_models.py pins repo-dict ↔ DTO parity so future
repo-row drift breaks the contract test before the endpoints.
