Task #253 — E2E CLI test scripts + FOCAS test-client CLI

The driver-layer integration tests confirm the driver sees the PLC, and
the Client.CLI tests confirm the client sees the server. Nothing glued
them end-to-end until this PR.

- scripts/e2e/_common.ps1: shared helpers — CLI invocation (published-
  binary OR `dotnet run` fallback), Test-Probe / Test-DriverLoopback /
  Test-ServerBridge (all return @{Passed;Reason} hashtables).
- scripts/e2e/test-<modbus|abcip|ablegacy|s7|focas|twincat>.ps1: per-
  driver three-stage script (probe → driver-loopback → server-bridge).
  AB Legacy / FOCAS / TwinCAT are gated behind *_TRUST_WIRE env vars
  since they need real hardware (#222) or a licensed runtime (#221).
- scripts/e2e/test-phase7-virtualtags.ps1: writes a Modbus HR, reads
  the server-side VirtualTag (VT = input * 2) back via OPC UA, triggers
  + clears a scripted alarm. Exercises the Phase 7 CachedTagUpstreamSource
  + ScriptedAlarmEngine path.
- scripts/e2e/test-all.ps1: reads e2e-config.json sidecar, runs each
  present driver, prints a FINAL MATRIX (PASS/FAIL/SKIP). Missing
  sections SKIP rather than fail hard.
- scripts/e2e/e2e-config.sample.json: commented sample — each dev's
  NodeIds are local-seed-specific so e2e-config.json is .gitignore-d.
- scripts/e2e/README.md: full walkthrough — prereqs, three-stage design,
  env-var gates, expected matrix, why this is separate from `dotnet test`.

Tasks #249-#251 shipped Modbus/AbCip/AbLegacy/S7/TwinCAT CLIs but left
FOCAS out. Since test-focas.ps1 needs it, the 6th CLI ships here:

- src/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.Cli: probe/read/write/subscribe
  commands, AssemblyName `otopcua-focas-cli`. WriteCommand.ParseValue
  handles the full FocasDataType enum (Bit/Byte/Int16/Int32/Float32/
  Float64/String — no UInt variants; the FOCAS protocol exposes signed
  PMC + Fanuc-Float only). Default DataType is Int16 to match the PMC
  register convention.

Full-solution build clean (0 errors). FOCAS CLI wired into
ZB.MOM.WW.OtOpcUa.slnx. No .Tests project for the FOCAS CLI yet —
symmetric with how ProbeCommand has no unit-testable pure logic in the
other 5 CLIs either; WriteCommand.ParseValue parity will land in a
follow-up to keep this PR scoped.

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

src/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.Cli/Program.cs

@@ -0,0 +1,12 @@
+using CliFx;
+
+return await new CliApplicationBuilder()
+    .AddCommandsFromThisAssembly()
+    .SetExecutableName("otopcua-focas-cli")
+    .SetDescription(
+        "OtOpcUa FOCAS test-client — ad-hoc probe + PMC/param/macro reads/writes + polled " +
+        "subscriptions against Fanuc CNCs via the FOCAS/2 protocol. Requires a real CNC + a " +
+        "licensed Fwlib32.dll on PATH (or next to the executable) — no public simulator " +
+        "exists. Addresses use FocasAddressParser syntax: R100, X0.0, PARAM:1815/0, MACRO:500.")
+    .Build()
+    .RunAsync(args);