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.Server/Dashboard/Hubs/EventsHub.cs

@@ -39,8 +39,8 @@ public sealed class EventsHub(
     /// The hub-level <see cref="AuthorizeAttribute"/> (<c>HubClientsPolicy</c>)
     /// only checks that the caller carries one of the dashboard roles, which by
     /// itself would let any Viewer subscribe to any session id they name. The
-    /// per-session decision is <see cref="IDashboardSessionAcl"/>'s
-    /// (SEC-25 / TST-15). The admin bypass is evaluated first, so an
+    /// per-session decision is <see cref="IDashboardSessionAcl"/>'s.
+    /// The admin bypass is evaluated first, so an
     /// Administrator joins any session id they name; every check below it
     /// applies to non-Admin callers only. For those: a Viewer sees a session
     /// only when its tags intersect their granted tags, an untagged session
@@ -95,16 +95,12 @@ public sealed class EventsHub(
         viewerRegistry.RemoveViewer(Context.ConnectionId, sessionId);
     }
 
-    /// <summary>
-    /// Releases every session subscription the dropped connection held. A browser
-    /// tab that closes never calls <see cref="UnsubscribeSession"/>, so without
-    /// this the session would look watched forever and the mirror would keep
-    /// cloning and sending events to an empty group.
-    /// </summary>
-    /// <param name="exception">The exception that terminated the connection, if any.</param>
-    /// <returns>A task representing the disconnect handling.</returns>
+    /// <inheritdoc />
     public override Task OnDisconnectedAsync(Exception? exception)
     {
+        // Release every session subscription the dropped connection held. A browser tab that
+        // closes never calls UnsubscribeSession, so without this the session would look watched
+        // forever and the mirror would keep cloning and sending events to an empty group.
         viewerRegistry.ReleaseConnection(Context.ConnectionId);
 
         return base.OnDisconnectedAsync(exception);