docs(audit): drivers/FOCAS-Test-Fixture.md — accuracy pass

STRUCTURAL
- docs/drivers/FOCAS-Test-Fixture.md line 140: replaced stale
  `Series/FixedTreePopulatesTests.cs` reference (file deleted) with
  `Series/WireBackendTests.cs` — the current home of all fixed-tree
  end-to-end integration tests (verified: ls Series/ shows only
  WireBackendTests.cs + WireBackendCoverageTests.cs).

STALE-STATUS
- Removed `**Status:** as of 2026-04-24` header (date-anchored, stale).
  The architecture description that followed was accurate; the date anchor
  served no purpose once the shim era is closed.

CODE-REALITY
- Line 55: TCP-probe skip gate now mentions `OTOPCUA_FOCAS_SIM_ENDPOINT`
  override (verified in FocasSimFixture.cs line 22 / 49).

FOCAS.md: no changes — all claims verified accurate against source.
- IAlarmSource implemented: FocasDriver.cs:21
- IWritable returns BadNotWritable: FocasDriver.cs (IWritable body)
- All capability interfaces listed in capability table confirmed in
  FocasDriver.cs:21 class declaration
- All linked files exist and resolve correctly

docs/drivers/FOCAS-Test-Fixture.md

@@ -2,8 +2,8 @@
 
 Coverage map + gap inventory for the FANUC FOCAS2 CNC driver.
 
-**Status:** as of 2026-04-24, OtOpcUa speaks FOCAS2 directly over TCP
+OtOpcUa speaks FOCAS2 directly over TCP via the pure-managed
-via the pure-managed [`Focas.Wire`](https://github.com/Ladder99/focas-mock/tree/main/dotnet/Focas.Wire)
+[`Focas.Wire`](https://github.com/Ladder99/focas-mock/tree/main/dotnet/Focas.Wire)
 client. Integration tests run the managed driver end-to-end against the
 vendored `focas-mock` Python server (at
 [`tests/.../Docker/focas-mock/`](../../tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.IntegrationTests/Docker/focas-mock/VENDORED.md))
@@ -51,8 +51,9 @@ message naming the CNC series + documented limit.
 `tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.IntegrationTests/` drives the
 managed `FocasDriver` end-to-end. A single gate:
 
-**Docker compose up** — tests skip when the TCP probe to
+**Docker compose up** — tests skip when the TCP probe fails, with a
-`localhost:8193` fails with a pointer to the compose command.
+pointer to the compose command. The endpoint defaults to `localhost:8193`
+and is overridable via `OTOPCUA_FOCAS_SIM_ENDPOINT`.
 
 When the mock is up, `WireFocasClient` dials it over TCP exactly like a
 real CNC, and the mock's native FOCAS Ethernet responder replies with
@@ -137,8 +138,8 @@ Or use `scripts/integration/run-focas.ps1` which wraps compose up / test
   — per-series compose profiles
 - `tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.IntegrationTests/FocasSimFixture.cs`
   — collection fixture + mock admin API client
-- `tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.IntegrationTests/Series/FixedTreePopulatesTests.cs`
+- `tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.IntegrationTests/Series/WireBackendTests.cs`
-  — fixed-tree end-to-end tests
+  — fixed-tree end-to-end tests (identity / axes / spindle / program / timers)
 - `tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.IntegrationTests/Series/WireBackendTests.cs`
   — pure-wire-backend end-to-end tests
 - `tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.Tests/FakeFocasClient.cs` —