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/Diagnostics/GatewayLogRedactorSeamTests.cs

@@ -4,6 +4,7 @@ namespace ZB.MOM.WW.MxGateway.Tests.Diagnostics;
 
 public sealed class GatewayLogRedactorSeamTests
 {
+    /// <summary>Redacting a log property containing a bearer API key masks the secret while preserving the key id prefix.</summary>
     [Fact]
     public void Redact_MasksApiKeyInClientIdentity()
     {