Initial commit: VMware vSphere API simulator scaffold.

Add the FastAPI app, PostgreSQL migrations, Docker/Helm packaging, API
contracts, docs, client examples, and the unit/integration/compatibility
test suite for local client and tooling labs without a real vCenter.

docs/domains/networking.md

@@ -0,0 +1,35 @@
+**Language / Язык:** [English](networking.md) | [Русский](../ru/domains/networking.md)
+
+# Networking
+
+Standard networks, distributed portgroups/switches, and host networking:
+[`app/vsphere/rest/router.py`](../../app/vsphere/rest/router.py),
+[`platform_rest.py`](../../app/vsphere/rest/platform_rest.py).
+
+## Endpoints
+
+| Method | Path | Notes |
+|---|---|---|
+| GET | `/api/vcenter/network` | Standard `Network` objects + `DistributedVirtualPortgroup` |
+| GET/POST | `/api/vcenter/network/dvs` | Distributed virtual switches |
+| POST | `/api/vcenter/network/dvpg` | Create a distributed portgroup |
+| GET | `/api/vcenter/host/{host}/networking` | DNS, default gateway, `vmk0` interface, routing |
+| GET/PUT/POST | `/api/appliance/networking` \| `/networking/dns/{hostname,servers,domains}` | vCenter appliance-level networking (see [Appliance](appliance.md)) |
+
+Legacy `GET /rest/vcenter/network` mirrors the list.
+
+## Highlights
+
+- Every VM's `nics[].value.backing` points at either a `STANDARD_PORTGROUP`
+  (`network-41`, "VM Network") or a `DISTRIBUTED_PORTGROUP`
+  (`dvportgroup-4N`, tagged with a `vlan_id`).
+- The default topology seeds one `VmwareDistributedVirtualSwitch`
+  (`dvs-51`, `mtu: 9000`) and 1–3 extra distributed portgroups depending on
+  profile size.
+- Host networking (`GET /api/vcenter/host/{host}/networking`) returns DNS
+  servers/domains, a default gateway, and a single `vmk0` management
+  interface with a deterministic IPv4 address per host index.
+- NSX-labelled Automation API paths (tier-0 gateway, projects, edges,
+  VPC/subnets) are seeded lab stand-ins under `namespace-management` — see
+  the "Platform surfaces" table in [API coverage](../api-coverage.md); they
+  are not a real NSX Manager.