feat(focas): OtOpcUa-owned otopcua-focas-fixture stack (#651) + FOCAS backlog docs (#633)

Fixture renamed off ignitionoee's otopcua-focas-sim, port 8193 published, project label,
default endpoint 10.100.0.35:8193; infra/dev-environment docs. FOCAS.md: MACRO:3901 parts
count, PMC override + cycle-time recipes, won't-do/blocked backlog.

Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe

infra/README.md

@@ -37,8 +37,8 @@ ssh dohertj2@10.100.0.35 'docker ps --filter label=project=lmxopcua --format "{{
   | Stack dir | Purpose |
   |---|---|
   | `/opt/otopcua-mssql` | central SQL (always-on) |
-  | `/opt/otopcua-modbus` · `/opt/otopcua-abcip` · `/opt/otopcua-s7` · `/opt/otopcua-opcuaclient` · `/opt/otopcua-mqtt` · `/opt/otopcua-mtconnect` | driver fixtures |
-  | `~/otopcua-ablegacy` · `~/otopcua-focas` | driver fixtures (user-owned) |
+  | `/opt/otopcua-modbus` · `/opt/otopcua-abcip` · `/opt/otopcua-s7` · `/opt/otopcua-opcuaclient` · `/opt/otopcua-mqtt` · `/opt/otopcua-mtconnect` · `/opt/otopcua-focas` | driver fixtures |
+  | `~/otopcua-ablegacy` | driver fixture (user-owned) |
   | `~/otopcua-harness` | Host.IntegrationTests real-mode deps (SQL + GLAuth) — see §4 |
 
 - The repo's `tests/.../Docker/` trees are the **source of truth**; the host dirs are mirrored
@@ -68,14 +68,22 @@ when it isn't running. Bring one up, `dotnet test`, tear down. Repo compose live
 | AB Legacy (PCCC) | `otopcua-ab-server` (PCCC mode) | `10.100.0.35:44818` | `AB_LEGACY_COMPOSE_PROFILE=<…> docker compose up -d` (stack `~/otopcua-ablegacy`) |
 | S7 | `otopcua-python-snap7` | `10.100.0.35:1102` | `docker compose --profile s7_1500 up -d` |
 | OpcUaClient | `mcr.microsoft.com/iotedge/opc-plc:2.14.10` | `opc.tcp://10.100.0.35:50000` | `docker compose up -d` |
-| FOCAS | `otopcua-focas-sim` (vendored focas-mock) | `10.100.0.35:8193` | `docker compose up -d` (stack `~/otopcua-focas`) |
+| FOCAS | `otopcua-focas-fixture` (vendored focas-mock, built on the host) | `10.100.0.35:8193` (published) | `docker compose up -d --build` (stack `/opt/otopcua-focas`; rsync the repo's FOCAS `Docker/` dir first) |
 | MQTT | `eclipse-mosquitto:2.0.22` (+ a publisher sidecar) | `10.100.0.35:8883` TLS+auth · `:1883` plaintext+auth | `MQTT_FIXTURE_USERNAME=otopcua MQTT_FIXTURE_PASSWORD=<pw> docker compose up -d` (stack `/opt/otopcua-mqtt`) |
 | MQTT — Sparkplug B | `otopcua-sparkplug-sim` (project-owned C# edge-node simulator) | same broker; group **`OtOpcUaSim`**, edge nodes **`EdgeA`** / **`EdgeB`**, `EdgeA` device **`Filler1`**, ~2 s cadence | `docker compose --profile sparkplug up -d` (same stack). Answers rebirth NCMDs; restart it to force a fresh birth |
 | MTConnect | `mtconnect/agent:2.7.0.12` + `python:3.13-alpine` adapter | `http://10.100.0.35:5000` | `docker compose up -d --wait` |
 
 **Endpoint overrides** point a suite at a real PLC instead of the sim:
 `MODBUS_SIM_ENDPOINT` · `AB_SERVER_ENDPOINT` · `S7_SIM_ENDPOINT` · `OPCUA_SIM_ENDPOINT` ·
-`MQTT_FIXTURE_ENDPOINT` / `MQTT_FIXTURE_PLAIN_ENDPOINT` · `MTCONNECT_AGENT_ENDPOINT`.
+`MQTT_FIXTURE_ENDPOINT` / `MQTT_FIXTURE_PLAIN_ENDPOINT` · `MTCONNECT_AGENT_ENDPOINT` · `OTOPCUA_FOCAS_SIM_ENDPOINT`.
+
+> **`otopcua-focas-sim` on the host is NOT ours (#651).** It is ignitionoee's mock (created by that
+> project's `provision-oee-focas.sh` for `ignition-site`; no published port, different defaults:
+> big-endian timers, position exponent 3, `fwlib30i64` profile). OtOpcUa's fixture is
+> `otopcua-focas-fixture`; the two once shared a name and overwrote each other. Never `docker rm -f`,
+> rebuild or `mock_patch` `otopcua-focas-sim` or any `ignition-*`/`oee-*` container from here. The stale
+> `~/otopcua-focas` dir on the host predates the rename — do not `compose up` it; retire it after
+> `/opt/otopcua-focas` is deployed.
 
 > **MQTT needs credentials + material, unlike the other fixtures.** The broker has **no anonymous
 > fallback on either listener** (deliberate — an anonymous broker would let a bad auth config pass),