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.Server/Dashboard/HubTokenService.cs

@@ -12,7 +12,7 @@ namespace ZB.MOM.WW.MxGateway.Server.Dashboard;
 /// protector; no separate signing keys are configured.
 /// </summary>
 /// <remarks>
-/// Server-043: this service is registered as a singleton in
+/// This service is registered as a singleton in
 /// <see cref="DashboardServiceCollectionExtensions.AddGatewayDashboard"/> and
 /// is shared by two consumer scopes: <c>DashboardHubConnectionFactory</c>
 /// (scoped, per-circuit; calls <see cref="Issue"/> from the cookie-authenticated
@@ -40,6 +40,7 @@ public sealed class HubTokenService
 
     /// <summary>Issues a bearer token carrying the user's identity and roles.</summary>
     /// <param name="user">The claims principal representing the user.</param>
+    /// <returns>The data-protected bearer token string.</returns>
     public string Issue(ClaimsPrincipal user)
     {
         ArgumentNullException.ThrowIfNull(user);
@@ -52,6 +53,7 @@ public sealed class HubTokenService
 
     /// <summary>Validates a token and returns the equivalent claims principal; null when invalid or expired.</summary>
     /// <param name="token">The token string to validate.</param>
+    /// <returns>The reconstructed <see cref="ClaimsPrincipal"/>, or <see langword="null"/> when the token is missing, invalid, or expired.</returns>
     public ClaimsPrincipal? Validate(string? token)
     {
         if (string.IsNullOrEmpty(token))
@@ -67,11 +69,6 @@ public sealed class HubTokenService
                 return null;
             }
 
-            // Server-039: reject a token whose payload carries no caller
-            // identity. A null/empty Name AND NameIdentifier would otherwise
-            // produce a principal that satisfies IsAuthenticated and IsInRole
-            // checks without any associated user, because the AuthenticationType
-            // (the HubToken scheme) is non-empty.
             if (string.IsNullOrEmpty(payload.Name) && string.IsNullOrEmpty(payload.NameIdentifier))
             {
                 return null;