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/Dashboard/DashboardSessionAdminServiceTests.cs

@@ -10,6 +10,7 @@ namespace ZB.MOM.WW.MxGateway.Tests.Gateway.Dashboard;
 public sealed class DashboardSessionAdminServiceTests
 {
     /// <summary>Verifies that a viewer cannot close a session.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task CloseSessionAsync_ViewerCannotManage()
     {
@@ -26,6 +27,7 @@ public sealed class DashboardSessionAdminServiceTests
     }
 
     /// <summary>Verifies that an admin can close a session.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task CloseSessionAsync_AdminClosesSession()
     {
@@ -43,6 +45,7 @@ public sealed class DashboardSessionAdminServiceTests
     }
 
     /// <summary>Verifies that closing a missing session returns a friendly error message.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task CloseSessionAsync_WhenSessionMissing_ReportsFriendlyError()
     {
@@ -62,6 +65,7 @@ public sealed class DashboardSessionAdminServiceTests
     }
 
     /// <summary>Verifies that a viewer cannot kill a worker.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task KillWorkerAsync_ViewerCannotManage()
     {
@@ -78,6 +82,7 @@ public sealed class DashboardSessionAdminServiceTests
     }
 
     /// <summary>Verifies that an admin can kill a worker.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task KillWorkerAsync_AdminKillsWorker()
     {
@@ -93,14 +98,11 @@ public sealed class DashboardSessionAdminServiceTests
         Assert.Equal(1, sessionManager.KillCount);
         Assert.Equal("session-1", sessionManager.LastKilledSessionId);
 
-        // Tests-028: pin the literal reason string so a future caller-side change is a deliberate
-        // test update rather than a silent drift. DashboardSessionAdminService passes a hard-coded
-        // "dashboard-admin-kill" so the worker-exit metric (mxgateway.workers.killed) carries a
-        // stable, machine-greppable reason tag.
         Assert.Equal("dashboard-admin-kill", sessionManager.LastKillReason);
     }
 
     /// <summary>Verifies that killing a worker with a blank session ID returns failure.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task KillWorkerAsync_BlankSessionId_ReturnsFailure()
     {
@@ -117,10 +119,11 @@ public sealed class DashboardSessionAdminServiceTests
     }
 
     /// <summary>
-    /// Tests-029: <c>CloseSessionAsync</c> has the same blank-session-id guard as
+    /// <c>CloseSessionAsync</c> has the same blank-session-id guard as
     /// <c>KillWorkerAsync</c> but previously had no parallel test. Coverage was asymmetric.
     /// A guard-removal regression on the close path would slip through.
     /// </summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task CloseSessionAsync_BlankSessionId_ReturnsFailure()
     {
@@ -148,12 +151,13 @@ public sealed class DashboardSessionAdminServiceTests
     }
 
     /// <summary>
-    /// Regression for Server-050: an unexpected (non-<see cref="SessionManagerException"/>)
+    /// Regression: an unexpected (non-<see cref="SessionManagerException"/>)
     /// exception from <c>CloseSessionAsync</c> — e.g. an <see cref="InvalidOperationException"/>
     /// or <see cref="IOException"/> surfaced from <c>RemoveSessionAsync</c>/<c>DisposeAsync</c> —
     /// must be converted to a friendly <see cref="DashboardSessionAdminResult.Fail(string)"/>
     /// rather than propagating raw into Blazor's error boundary.
     /// </summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task CloseSessionAsync_WhenManagerThrowsUnexpected_ReturnsFriendlyFail()
     {
@@ -173,8 +177,9 @@ public sealed class DashboardSessionAdminServiceTests
     }
 
     /// <summary>
-    /// Regression for Server-050: same friendly-fail contract for the Kill path.
+    /// Regression: same friendly-fail contract for the Kill path.
     /// </summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task KillWorkerAsync_WhenManagerThrowsUnexpected_ReturnsFriendlyFail()
     {