rename: prefix gateway projects/namespaces with ZB.MOM.WW + sln→slnx

Apply the ZB.MOM.WW. prefix to all gateway-side projects, folders,
.csproj/.sln contents, C# namespaces, using directives, generated proto
C# (csharp_namespace + checked-in generated files), InternalsVisibleTo
attributes, project-name string literals (LoadProject, .sln lookups,
worker exe paths, staticwebassets manifest), and the install/script/doc
references that point at any of the above. Migrate the solution from
.sln to .slnx via `dotnet sln migrate` and delete the old file.

External-runtime identifiers are intentionally NOT prefixed so external
configuration keeps working:
- GatewayMetrics.cs MeterName ("MxGateway.Server")
- DashboardAuthenticationDefaults Scheme/Policy ("MxGateway.Dashboard")
- GatewayRequestLoggingMiddleware logger category ("MxGateway.Request")
- StaRuntime thread name ("MxGateway.Worker.STA")
- appsettings.json root section "MxGateway" + env-var prefix
  MxGateway__... and secret-name MxGateway:ApiKeyPepper
- C:\ProgramData\MxGateway\ data dir paths

Also fixes two tests that were not rename-related but became visible
while validating the rename:

- WorkerLiveMxAccessSmokeTests.ShutDownAsync: cancellation that the
  gateway service correctly maps to RpcException(Cancelled) per gRPC
  convention was being misclassified as a stream fault. Added a sibling
  catch on RpcException with StatusCode.Cancelled.

- IntegrationTestEnvironment.ResolveRepositoryRoot: extracted IsRepositoryRoot
  and made it accept either a .git marker OR a .sln/.slnx next to src/
  so the worker-exe walker works in non-git working copies.

clients/proto/proto-inputs.json's protoRoot updated to point at
src/ZB.MOM.WW.MxGateway.Contracts/Protos.

Verified by `dotnet build` and a full `dotnet test` of the .slnx with
MXGATEWAY_RUN_LIVE_{MXACCESS,LDAP,GALAXY}_TESTS=1:
  Tests: 472/472 pass
  Worker.Tests: 280/280 pass (4 dev-rig [Fact(Skip=...)] skipped)
  IntegrationTests: 18/18 pass

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

src/ZB.MOM.WW.MxGateway.Server/Grpc/MxAccessGrpcMapper.cs

@@ -0,0 +1,175 @@
+using Google.Protobuf.WellKnownTypes;
+using ZB.MOM.WW.MxGateway.Contracts.Proto;
+
+namespace ZB.MOM.WW.MxGateway.Server.Grpc;
+
+/// <summary>
+/// Maps between worker IPC types and gRPC contract types.
+/// </summary>
+public sealed class MxAccessGrpcMapper
+{
+    private readonly TimeProvider _timeProvider;
+
+    /// <summary>
+    /// Initializes the mapper with an optional time provider.
+    /// </summary>
+    /// <param name="timeProvider">Time provider for timestamps; defaults to system time if null.</param>
+    public MxAccessGrpcMapper(TimeProvider? timeProvider = null)
+    {
+        _timeProvider = timeProvider ?? TimeProvider.System;
+    }
+
+    /// <summary>
+    /// Maps a gRPC MX command request to a worker command.
+    /// </summary>
+    /// <param name="request">Request payload.</param>
+    public WorkerCommand MapCommand(MxCommandRequest request)
+    {
+        ArgumentNullException.ThrowIfNull(request);
+        ArgumentNullException.ThrowIfNull(request.Command);
+
+        return new WorkerCommand
+        {
+            Command = request.Command.Clone(),
+            EnqueueTimestamp = Timestamp.FromDateTimeOffset(_timeProvider.GetUtcNow()),
+        };
+    }
+
+    /// <summary>
+    /// Maps a worker command reply to a gRPC MX command reply.
+    /// </summary>
+    /// <param name="reply">Worker command reply.</param>
+    public MxCommandReply MapCommandReply(WorkerCommandReply reply)
+    {
+        ArgumentNullException.ThrowIfNull(reply);
+
+        if (reply.Reply is null)
+        {
+            return new MxCommandReply
+            {
+                ProtocolStatus = ProtocolViolation("Worker command reply did not contain a public reply payload."),
+            };
+        }
+
+        return reply.Reply.Clone();
+    }
+
+    /// <summary>
+    /// Maps a worker event to a gRPC MX event.
+    /// </summary>
+    /// <param name="workerEvent">Worker event to map.</param>
+    public MxEvent MapEvent(WorkerEvent workerEvent)
+    {
+        ArgumentNullException.ThrowIfNull(workerEvent);
+
+        return workerEvent.Event?.Clone() ?? new MxEvent
+        {
+            Family = MxEventFamily.Unspecified,
+            RawStatus = "Worker event did not contain a public event payload.",
+        };
+    }
+
+    /// <summary>
+    /// Creates an OK protocol status.
+    /// </summary>
+    /// <param name="message">Status message.</param>
+    public static ProtocolStatus Ok(string message = "OK")
+    {
+        return new ProtocolStatus
+        {
+            Code = ProtocolStatusCode.Ok,
+            Message = message,
+        };
+    }
+
+    /// <summary>
+    /// Creates an InvalidRequest protocol status.
+    /// </summary>
+    /// <param name="message">Status message.</param>
+    public static ProtocolStatus InvalidRequest(string message)
+    {
+        return new ProtocolStatus
+        {
+            Code = ProtocolStatusCode.InvalidRequest,
+            Message = message,
+        };
+    }
+
+    /// <summary>
+    /// Creates a SessionNotFound protocol status.
+    /// </summary>
+    /// <param name="message">Status message.</param>
+    public static ProtocolStatus SessionNotFound(string message)
+    {
+        return new ProtocolStatus
+        {
+            Code = ProtocolStatusCode.SessionNotFound,
+            Message = message,
+        };
+    }
+
+    /// <summary>
+    /// Creates a SessionNotReady protocol status.
+    /// </summary>
+    /// <param name="message">Status message.</param>
+    public static ProtocolStatus SessionNotReady(string message)
+    {
+        return new ProtocolStatus
+        {
+            Code = ProtocolStatusCode.SessionNotReady,
+            Message = message,
+        };
+    }
+
+    /// <summary>
+    /// Creates a WorkerUnavailable protocol status.
+    /// </summary>
+    /// <param name="message">Status message.</param>
+    public static ProtocolStatus WorkerUnavailable(string message)
+    {
+        return new ProtocolStatus
+        {
+            Code = ProtocolStatusCode.WorkerUnavailable,
+            Message = message,
+        };
+    }
+
+    /// <summary>
+    /// Creates a Timeout protocol status.
+    /// </summary>
+    /// <param name="message">Status message.</param>
+    public static ProtocolStatus Timeout(string message)
+    {
+        return new ProtocolStatus
+        {
+            Code = ProtocolStatusCode.Timeout,
+            Message = message,
+        };
+    }
+
+    /// <summary>
+    /// Creates a Canceled protocol status.
+    /// </summary>
+    /// <param name="message">Status message.</param>
+    public static ProtocolStatus Canceled(string message)
+    {
+        return new ProtocolStatus
+        {
+            Code = ProtocolStatusCode.Canceled,
+            Message = message,
+        };
+    }
+
+    /// <summary>
+    /// Creates a ProtocolViolation protocol status.
+    /// </summary>
+    /// <param name="message">Status message.</param>
+    public static ProtocolStatus ProtocolViolation(string message)
+    {
+        return new ProtocolStatus
+        {
+            Code = ProtocolStatusCode.ProtocolViolation,
+            Message = message,
+        };
+    }
+}