docs(src): add missing XML docs and strip tracking-ID comments

Sweep of 203 source files resolving CommentChecker findings: add
<summary>/<param>/<returns>/<inheritdoc> where missing, and remove
resolved task/issue tracking markers (Tests-NNN, Worker-NNN, Server-NNN,
Task N) from code comments. Comment/doc-only — no logic changes.
Server+Tests build clean under TreatWarningsAsErrors.

src/ZB.MOM.WW.MxGateway.Tests/Gateway/GatewayApplicationTests.cs

@@ -15,6 +15,7 @@ namespace ZB.MOM.WW.MxGateway.Tests.Gateway;
 public sealed class GatewayApplicationTests
 {
     /// <summary>Verifies that Build maps the canonical three health tiers.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Build_MapsCanonicalHealthEndpoints()
     {
@@ -43,12 +44,13 @@ public sealed class GatewayApplicationTests
 
     /// <summary>
     /// Verifies that Build registers the gateway's browse-scope provider so it wins over the
-    /// shared library's no-op default (Server-060). The per-API-key browse-subtree scoping
+    /// shared library's no-op default. The per-API-key browse-subtree scoping
     /// depends on <c>AddSingleton&lt;IGalaxyBrowseScopeProvider, GatewayBrowseScopeProvider&gt;</c>
     /// running before <c>AddZbGalaxyRepository</c>, whose <c>TryAddSingleton</c> default
     /// (NullGalaxyBrowseScopeProvider → full hierarchy) must lose. If this registration order ever
     /// regressed, every metadata-scoped key would silently see the entire Galaxy hierarchy.
     /// </summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Build_RegistersGatewayBrowseScopeProviderOverLibraryDefault()
     {
@@ -61,6 +63,7 @@ public sealed class GatewayApplicationTests
     }
 
     /// <summary>Verifies that Build registers the gateway metrics service.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Build_RegistersGatewayMetrics()
     {
@@ -72,6 +75,7 @@ public sealed class GatewayApplicationTests
     }
 
     /// <summary>Verifies that Build mounts the Prometheus /metrics scrape endpoint.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Build_MapsMetricsEndpoint()
     {
@@ -94,6 +98,7 @@ public sealed class GatewayApplicationTests
     }
 
     /// <summary>Verifies that Build maps dashboard and authentication endpoints when the dashboard is enabled.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Build_WhenDashboardEnabled_MapsBlazorDashboardAndAuthEndpoints()
     {
@@ -123,6 +128,7 @@ public sealed class GatewayApplicationTests
     }
 
     /// <summary>Verifies that the dashboard login, logout, and denied endpoints allow anonymous access.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Build_WhenDashboardEnabled_AuthEndpointsAllowAnonymousAccess()
     {
@@ -152,6 +158,7 @@ public sealed class GatewayApplicationTests
     }
 
     /// <summary>Verifies that dashboard Razor component routes require the dashboard viewer policy.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Build_WhenDashboardEnabled_ComponentRoutesRequireAuthorization()
     {
@@ -180,6 +187,7 @@ public sealed class GatewayApplicationTests
     }
 
     /// <summary>Verifies that dashboard routes are registered at root when enabled.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Build_WhenDashboardEnabled_RegistersDashboardRoutesAtRoot()
     {
@@ -205,6 +213,7 @@ public sealed class GatewayApplicationTests
     }
 
     /// <summary>Verifies that dashboard routes are not mapped when disabled.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Build_WhenDashboardDisabled_DoesNotMapDashboardRoutes()
     {
@@ -221,6 +230,7 @@ public sealed class GatewayApplicationTests
     /// <param name="key">Configuration key to override.</param>
     /// <param name="value">Invalid configuration value.</param>
     /// <param name="expectedFailure">Expected validation error message.</param>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Theory]
     [InlineData(
         "MxGateway:Worker:ExecutablePath",