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/Dashboard/Components/Pages/WorkersPage.razor

@@ -0,0 +1,54 @@
+@page "/workers"
+@page "/dashboard/workers"
+@inherits DashboardPageBase
+
+<PageTitle>Dashboard Workers</PageTitle>
+
+@if (Snapshot is null)
+{
+    <div class="empty-state">Loading workers.</div>
+}
+else
+{
+    <div class="dashboard-page-header">
+        <div>
+            <h1>Workers</h1>
+            <div class="text-secondary">@Snapshot.Workers.Count worker rows</div>
+        </div>
+    </div>
+
+    <section class="dashboard-section">
+        @if (Snapshot.Workers.Count == 0)
+        {
+            <div class="empty-state">No worker processes are attached.</div>
+        }
+        else
+        {
+            <div class="table-responsive">
+                <table class="table table-sm align-middle dashboard-table">
+                    <thead>
+                        <tr>
+                            <th scope="col">Process</th>
+                            <th scope="col">State</th>
+                            <th scope="col">Session</th>
+                            <th scope="col">Heartbeat</th>
+                            <th scope="col">Fault</th>
+                        </tr>
+                    </thead>
+                    <tbody>
+                        @foreach (DashboardWorkerSummary worker in Snapshot.Workers)
+                        {
+                            <tr>
+                                <td>@(worker.ProcessId?.ToString(System.Globalization.CultureInfo.InvariantCulture) ?? "-")</td>
+                                <td><StatusBadge Text="@worker.State.ToString()" /></td>
+                                <td><NavLink href="@($"sessions/{Uri.EscapeDataString(worker.SessionId)}")"><code>@worker.SessionId</code></NavLink></td>
+                                <td>@DashboardDisplay.DateTime(worker.LastHeartbeatAt)</td>
+                                <td>@DashboardDisplay.Text(worker.LastFault)</td>
+                            </tr>
+                        }
+                    </tbody>
+                </table>
+            </div>
+        }
+    </section>
+}