Dashboard: fix API keys page stuck on "Loading"

ApiKeysPage.OnInitializedAsync overrode the base without chaining, so
DashboardPageBase's Snapshot seed and hub connect never ran and the
page rendered the null-snapshot empty state forever.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/ZB.MOM.WW.MxGateway.Server/Dashboard/Components/Pages/ApiKeysPage.razor

@@ -225,6 +225,8 @@ else
 
     protected override async Task OnInitializedAsync()
     {
+        await base.OnInitializedAsync().ConfigureAwait(false);
+
         AuthenticationState authenticationState = await AuthenticationStateProvider.GetAuthenticationStateAsync()
             .ConfigureAwait(false);
         CanManageApiKeys = ApiKeyManagementService.CanManage(authenticationState.User);