FOCAS — retire Tier-C split, inline managed wire client, make read-only

Migration closes the FOCAS Tier-C architecture. OtOpcUa previously had
`Driver.FOCAS.Host` (NSSM-wrapped Windows service loading Fwlib64.dll via
P/Invoke) + `Driver.FOCAS.Shared` (MessagePack IPC contracts) + a C shim
DLL stand-in for unit tests. All of it is deleted; the driver is now a
single in-process managed assembly talking the FOCAS/2 Ethernet binary
protocol directly on TCP:8193.

Architecture

- Pure-managed `FocasWireClient` inlined at `src/.../Driver.FOCAS/Wire/`
  (owner-imported — see Wire/FocasWireClient.cs for the full surface).
  Opens two TCP sockets, runs the initiate handshake, serialises requests
  on socket 2 through a semaphore, closes cleanly with PDU + socket
  teardown. Both sync `IDisposable` and async `IAsyncDisposable`.
- `WireFocasClient` (same folder) adapts the wire client to OtOpcUa's
  `IFocasClient` surface — fixed-tree reads, PARAM/MACRO/PMC addresses,
  alarms. Writes return `BadNotWritable` by design — OtOpcUa is read-only
  against FOCAS.
- `FocasDriverFactoryExtensions` now accepts `"Backend": "wire"` (default)
  and `"Backend": "unimplemented"`. Legacy `ipc` and `fwlib` backends are
  rejected at startup with a diagnostic pointing at the migration doc.

Deletions

- `src/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.Host/` — whole project + Ipc/,
  Backend/, Stability/, Program.cs.
- `src/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.Shared/` — Contracts/, FrameReader,
  FrameWriter, whole project.
- `tests/...Driver.FOCAS.Host.Tests/` + `.Shared.Tests/` — whole projects.
- `src/.../Driver.FOCAS/FwlibNative.cs` + `FwlibFocasClient.cs` — 21
  P/Invokes + 7 `Pack=1` marshalling structs + the Fwlib-backed
  `IFocasClient` implementation.
- `src/.../Driver.FOCAS/Ipc/` + `Supervisor/` — IPC client wrapper +
  Host-process supervisor (backoff, circuit breaker, heartbeat, post-
  mortem reader, process launcher).
- `scripts/install/Install-FocasHost.ps1` — NSSM service installer.
- `tests/.../Driver.FOCAS.Tests/{IpcFocasClientTests, IpcLoopback,
  FwlibNativeHelperTests, PostMortemReaderCompatibilityTests,
  SupervisorTests, FocasDriverFactoryExtensionsTests}.cs` — tests that
  exercised the retired surfaces.
- `tests/.../Driver.FOCAS.IntegrationTests/Shim/` — the zig-built C shim
  DLL that masqueraded as Fwlib64.dll.

Solution changes

- `ZB.MOM.WW.OtOpcUa.slnx` drops the 4 retired project refs.
- `src/.../Driver.FOCAS.csproj` drops the Shared ProjectReference, adds
  `Microsoft.Extensions.Logging.Abstractions` for the optional `ILogger`
  hook in `FocasWireClient`.
- `src/.../Driver.FOCAS.Cli.csproj` drops the six `<Content Include>`
  entries that copied `vendor/fanuc/*.dll` into the CLI bin. CLI now uses
  `WireFocasClient` directly.
- `FocasDriver` default factory flips to `Wire.WireFocasClientFactory`.

Integration tests

- New `tests/.../Driver.FOCAS.IntegrationTests/` project covering fixed-
  tree reads (identity, axes, dynamic, program, operation mode, timers,
  spindle load + max RPM, servo meters), user-authored PARAM / MACRO /
  PMC reads, `DiscoverAsync` emission, `SubscribeAsync` + `OnDataChange`,
  `IAlarmSource` raise/clear transitions, and `ProbeAsync` /
  `OnHostStatusChanged`. 9 e2e tests against the focas-mock fixture
  (Docker container with the vendored Python mock's native FOCAS/2
  Ethernet responder).
- `scripts/integration/run-focas.ps1` orchestrates compose up → tests →
  compose down. Dropped the shim-build stage + DLL-copy step + the split
  testhost workaround (the latter only existed because of native-DLL
  lifecycle bugs the shim tripped).
- Docker compose collapses from 11 per-series services to one `focas-sim`
  service. Tests seed per-series state via `mock_load_profile` at test
  start.
- Vendored focas-mock snapshot refreshed to pick up upstream's native
  FOCAS/2 Ethernet responder (was 660 lines, now 1018) — the
  pre-refresh snapshot only spoke the JSON admin protocol.

Tests

- 145/145 unit tests in `Driver.FOCAS.Tests` pass (was 208 pre-deletion;
  63 removed tests exercised the retired IPC/shim/supervisor/Fwlib
  surfaces).
- 9/9 integration tests pass against the refreshed mock.
- `FocasScaffoldingTests.Unimplemented_factory_throws_on_Create…` updated
  to assert the new diagnostic message pointing at
  `docs/drivers/FOCAS.md` rather than the now-gone `Fwlib64.dll`.

Docs

- `docs/drivers/FOCAS.md` rewritten for the managed wire topology —
  deployment collapses to one `"Backend": "wire"` config block, no
  separate service, no DLL deployment, no pipe ACL.
- `docs/drivers/FOCAS-Test-Fixture.md` updated — single TCP probe skip
  gate instead of TCP + shim probe; fewer moving parts.
- `docs/drivers/README.md` row for FOCAS reflects the Tier-A managed
  topology (previously listed Tier-C + `Fwlib64.dll` P/Invoke).
- `docs/Driver.FOCAS.Cli.md` drops the Tier-C architecture-note section.
- `docs/v2/implementation/focas-isolation-plan.md` marked historical —
  the plan it documents was executed then superseded by the wire client.
- `docs/v2/v2-release-readiness.md` re-audited 2026-04-24. Phase 5
  driver complement closed. FOCAS change-log entry added.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scripts/integration/README.md

@@ -0,0 +1,87 @@
+# Integration runners
+
+Scripts that orchestrate multi-component integration-test loops —
+each one wires up docker fixtures, support binaries, and `dotnet test`
+in sequence so a developer (or a CI agent) can get from "freshly
+cloned repo" to "green integration suite" with one command.
+
+Unlike `scripts/e2e/test-*.ps1` (which drive the built server through
+the CLI for black-box coverage), scripts in this folder operate
+**below** the server layer — they bring up the raw fixtures the
+driver-level `IntegrationTests` projects need.
+
+## Scripts
+
+| Script | Purpose |
+|--------|---------|
+| [`run-focas.ps1`](run-focas.ps1) | FOCAS driver: builds shim DLLs + starts focas-mock docker + copies shim into test bin + runs `WireCompatGatedTests` + `FocasSimSmokeTests` + tears down docker |
+
+## run-focas.ps1
+
+### Prerequisites
+
+- **Windows + PowerShell 7+**
+- **.NET 10 SDK** — `dotnet --version` prints 10.x
+- **Native C compiler** — one of:
+  - Visual Studio Build Tools with the C++ workload (then run from an
+    "x64 Native Tools Command Prompt for VS" shell), or
+  - Zig (`zig.exe` on PATH) as a drop-in alternative
+- **Docker Desktop** running, OR pass `-SkipDocker` and run the mock
+  externally
+
+### One-shot run
+
+```powershell
+cd C:\Users\dohertj2\Desktop\lmxopcua
+pwsh .\scripts\integration\run-focas.ps1
+```
+
+That's the default invocation: thirtyone profile, debug build,
+docker cleans up on exit.
+
+### Development iteration
+
+Re-run the tests without rebuilding the shim or restarting docker:
+
+```powershell
+# First run bootstraps everything + keeps the mock up.
+pwsh .\scripts\integration\run-focas.ps1 -KeepDocker
+
+# Iterate on test bodies without re-doing the slow steps.
+pwsh .\scripts\integration\run-focas.ps1 -SkipShimBuild -SkipDocker
+```
+
+### Per-series runs
+
+```powershell
+pwsh .\scripts\integration\run-focas.ps1 -Profile thirty     # 30i series
+pwsh .\scripts\integration\run-focas.ps1 -Profile zerod      # 0i-D
+pwsh .\scripts\integration\run-focas.ps1 -Profile powermotion
+```
+
+Full profile list is in
+`tests/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.IntegrationTests/Docker/docker-compose.yml`.
+
+### Exit codes
+
+| Code | Meaning |
+|------|---------|
+| 0 | All tests passed or cleanly skipped |
+| 1 | `dotnet test` reported failures |
+| 2 | The runner itself crashed (missing file, unexpected exception) |
+| 3 | No C compiler detected for shim build |
+| 4 | Docker CLI not on PATH |
+
+### CI integration
+
+Wire this into the project's CI runner (Gitea Actions, Jenkins,
+whatever's hosting this repo) by calling:
+
+```yaml
+- name: FOCAS integration
+  shell: pwsh
+  run: ./scripts/integration/run-focas.ps1
+```
+
+The script is idempotent; a previous run's `docker compose down`
+failure won't block the next one.