Resolve all high-severity architecture review findings

src/ZB.MOM.WW.ScadaBridge.CentralUI/Auth/SiteScopeService.cs

@@ -37,7 +37,6 @@ namespace ZB.MOM.WW.ScadaBridge.CentralUI.Auth;
 public sealed class SiteScopeService
 {
     private readonly AuthenticationStateProvider _authStateProvider;
-    private (bool IsSystemWide, IReadOnlySet<int> Sites)? _cached;
 
     /// <summary>Initializes a new instance of <see cref="SiteScopeService"/>.</summary>
     /// <param name="authStateProvider">The Blazor authentication state provider used to read the current user's claims.</param>
@@ -92,10 +91,7 @@ public sealed class SiteScopeService
 
     private async Task<(bool IsSystemWide, IReadOnlySet<int> Sites)> ResolveAsync()
     {
-        if (_cached is { } cached)
-            return cached;
-
-        var state = await _authStateProvider.GetAuthenticationStateAsync();
+        var state = await _authStateProvider.GetAuthoritativeStateAsync();
 
         // Administrator => system-wide, whatever SiteId claims are present. Read
         // the role CLAIM rather than IsInRole: the principal's role claim type is
@@ -103,6 +99,9 @@ public sealed class SiteScopeService
         // by SessionClaimBuilder, and the comparison is OrdinalIgnoreCase to match
         // ManagementActor's — IsInRole compares claim VALUES ordinally, which would
         // make the two sides disagree on a differently-cased role name.
+        if (state.User.Identity?.IsAuthenticated != true)
+            return (false, new HashSet<int>());
+
         var isAdministrator = state.User
             .FindAll(JwtTokenService.RoleClaimType)
             .Any(c => string.Equals(c.Value, Roles.Administrator, StringComparison.OrdinalIgnoreCase));
@@ -126,7 +125,6 @@ public sealed class SiteScopeService
         // unrestricted deployer (this service is the sole
         // site-scoping mechanism — there is no separate handler to mirror).
         var result = (IsSystemWide: isAdministrator || ids.Count == 0, Sites: (IReadOnlySet<int>)ids);
-        _cached = result;
         return result;
     }
 }