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>

docs/Diagnostics.md

@@ -1,6 +1,6 @@
 # Gateway Diagnostics
 
-The diagnostics subsystem provides structured logging, credential redaction, and request-scoped log enrichment for the gateway. It lives under `src/MxGateway.Server/Diagnostics/` and is wired into the ASP.NET Core pipeline so every gRPC and HTTP request carries the same correlation fields.
+The diagnostics subsystem provides structured logging, credential redaction, and request-scoped log enrichment for the gateway. It lives under `src/ZB.MOM.WW.MxGateway.Server/Diagnostics/` and is wired into the ASP.NET Core pipeline so every gRPC and HTTP request carries the same correlation fields.
 
 ## Goals
 
@@ -162,7 +162,7 @@ public static IApplicationBuilder UseGatewayRequestLoggingScope(this IApplicatio
     {
         ILogger logger = context.RequestServices
             .GetRequiredService<ILoggerFactory>()
-            .CreateLogger("MxGateway.Request");
+            .CreateLogger("ZB.MOM.WW.MxGateway.Request");
 
         using IDisposable? scope = logger.BeginGatewayScope(new GatewayLogScope(
             SessionId: ReadHeader(context, SessionIdHeaderName),
@@ -188,7 +188,7 @@ The scope is keyed off four custom headers and the standard `authorization` head
 
 The numeric headers use `int.TryParse` and `ulong.TryParse`; missing or unparseable values become `null` and are dropped by `GatewayLogScope.ToDictionary`. This keeps the middleware tolerant of clients that do not yet emit every header, which matters because the earliest call in a session (`OpenSession`) has no `SessionId` to send.
 
-The logger category is `MxGateway.Request`, which lets operators filter the request scope events independently from per-component categories.
+The logger category is `ZB.MOM.WW.MxGateway.Request`, which lets operators filter the request scope events independently from per-component categories.
 
 ### Pipeline ordering
 
@@ -213,7 +213,7 @@ The order matters: putting the logging scope first ensures that authentication f
 
 - `GatewayLogScope.ToDictionary` redacts `ClientIdentity` whenever a scope is materialized.
 - `DashboardRedactor.Redact` delegates to `RedactClientIdentity` for any value containing the `mxgw_` marker, then falls back to a marker-keyword check for fields like `password` or `token`. This keeps dashboard renders aligned with log redaction.
-- `MxGateway.Tests/Diagnostics/GatewayLogRedactorTests.cs` covers each redaction branch, including the assertion that `WriteSecured` values stay redacted even when `valueLoggingEnabled` is true.
+- `ZB.MOM.WW.MxGateway.Tests/Diagnostics/GatewayLogRedactorTests.cs` covers each redaction branch, including the assertion that `WriteSecured` values stay redacted even when `valueLoggingEnabled` is true.
 
 ## Related Documentation