feat(scripting): out-of-process pre-emptible script runner behind Scripting:Runner (lmxopcua#780 P1)

Opt-in (Scripting:Runner=OutOfProcess; InProcess stays the default and its code path is unchanged). Implements
the P1 slice of docs/plans/2026-11-09-out-of-process-script-runner-design.md with the owner's §14 decisions:

- Options: Scripting:Runner (InProcess | Shadow | OutOfProcess), Scripting:Runner:Seams, Scripting:Worker:*
  (Shards 2, HardGrace max(1 s,T), HeapLimitBytes 512 MiB, QuarantineAfterKills 2, UnavailableGrace 5 s,
  IsolationProbationRuns 20, PeCacheDir validated absolute + outside the content root (fail closed),
  ExecutablePath). Shadow is not implemented yet: runs InProcess with a startup Warning.
- Core.Scripting: IScriptRunner seam + InProcessScriptRunner (today's guard, the parity baseline).
- Core.Scripting.Protocol: protobuf envelopes, 4-byte LE framing (zero/oversize/truncated/garbage refused),
  Variant carrying the exact CLR type; unsupported types are explicit failures.
- ScriptWorker app: compiles in the worker, P-thread scheduler, host-driven soft cancel, fail-fast
  watchdog, heartbeats, ctx.Logger forwarding, exits on pipe EOF / parent gone, forbidden-assembly
  self-check; Akka and Grpc.Core.Api excluded from its folder. Shipped in script-worker/ (Build + Publish).
- Core.Scripting.OutOfProcess: K shards + isolation worker, soft T / hard T+G kill, attribution
  (deadline kill = one key; crash = suspects -> isolation; isolation crash = strike), kill-strike
  quarantine, backoff 250 ms -> 30 s, fail closed, cleared allow-listed env, nonce + pid handshake on a
  current-user pipe, Windows Job Object.
- VirtualTag + Calculation seams use the runner when selected; a runner-side failure (worker restarted /
  runner unavailable) publishes BadResourceUnavailable (0x80040000) — ScadaBridge#112. Script faults keep
  BadInternalError. The scripted-alarm seam stays in process (alarms last).

Tests: new ZB.MOM.WW.OtOpcUa.ScriptWorker.Tests (Category=ScriptWorker, real processes; green on macOS and
on windev/Windows), seam tests in Host/Runtime/Calculation suites; mutation-checked.

Claude-Session: https://claude.ai/code/session_01GT67AEHd2Acv1YPwGfXEoV

src/Server/ZB.MOM.WW.OtOpcUa.ScriptWorker/Program.cs

@@ -0,0 +1,36 @@
+using System.IO.Pipes;
+using ZB.MOM.WW.OtOpcUa.Core.Scripting.Protocol;
+
+namespace ZB.MOM.WW.OtOpcUa.ScriptWorker;
+
+/// <summary>Entry point: connect to the host's pipe named in the environment and serve until told to stop.</summary>
+internal static class Program
+{
+    private static async Task<int> Main()
+    {
+        var pipeName = Environment.GetEnvironmentVariable(ScriptWorkerEnvironment.PipeName);
+        var nonce = Environment.GetEnvironmentVariable(ScriptWorkerEnvironment.Nonce);
+        if (string.IsNullOrEmpty(pipeName) || string.IsNullOrEmpty(nonce))
+        {
+            await Console.Error.WriteLineAsync("ScriptWorker: launched without a pipe name or nonce; exiting.");
+            return ScriptWorkerEnvironment.ExitProtocolFault;
+        }
+        _ = int.TryParse(Environment.GetEnvironmentVariable(ScriptWorkerEnvironment.ParentPid), out var parentPid);
+
+        // CurrentUserOnly: the client verifies the server end is owned by this account as well.
+        var pipe = new NamedPipeClientStream(".", pipeName, PipeDirection.InOut,
+            PipeOptions.Asynchronous | PipeOptions.CurrentUserOnly);
+        try
+        {
+            await pipe.ConnectAsync(TimeSpan.FromSeconds(10), CancellationToken.None);
+        }
+        catch (Exception ex)
+        {
+            await Console.Error.WriteLineAsync($"ScriptWorker: could not connect to the host pipe: {ex.Message}");
+            return ScriptWorkerEnvironment.ExitProtocolFault;
+        }
+
+        var host = new WorkerHost(pipe, nonce, parentPid);
+        return await host.RunAsync();
+    }
+}