docs: strip task-tracking IDs from code comments and fill missing XML docs

Tracking IDs are review bookkeeping that rots in shipped source; the rationale they tagged is kept. Comment-only change (CommentChecker 458 -> 16 false positives).

src/ZB.MOM.WW.MxGateway.Tests/Gateway/Sessions/SessionManagerTests.cs

@@ -41,7 +41,7 @@ public sealed class SessionManagerTests
     ///     Verifies the pipe name stays short enough that its Unix-domain-socket path
     ///     (TMPDIR + "CoreFxPipe_" + name) fits the 104-byte macOS sun_path limit under the
     ///     default per-user TMPDIR (~49 chars), and keeps the pid + session-guid uniqueness
-    ///     contract (NEXT-01).
+    ///     contract.
     /// </summary>
     /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
@@ -110,7 +110,7 @@ public sealed class SessionManagerTests
     }
 
     /// <summary>
-    ///     Verifies a session inherits the owning API key's dashboard-visibility tags (SEC-25),
+    ///     Verifies a session inherits the owning API key's dashboard-visibility tags,
     ///     compared ordinal-ignore-case so a differently cased grant still matches.
     /// </summary>
     /// <returns>A task that represents the asynchronous operation.</returns>