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/Configuration/GatewayOptionsTests.cs

@@ -123,12 +123,14 @@ public sealed class GatewayOptionsTests
             StringComparison.Ordinal);
     }
 
+    /// <summary>Verifies that <see cref="DashboardOptions.DisableLogin"/> defaults to <see langword="false"/>.</summary>
     [Fact]
     public void DashboardOptions_DisableLogin_DefaultsToFalse()
     {
         Assert.False(new DashboardOptions().DisableLogin);
     }
 
+    /// <summary>Verifies that <see cref="DashboardOptions.AutoLoginUser"/> defaults to <see langword="null"/>.</summary>
     [Fact]
     public void DashboardOptions_AutoLoginUser_DefaultsToNull()
     {