fix(central-ui): resolve CentralUI-020..025 — auth-ping idle logout, DebugView race, push-handler disposal guard, JS-interop catch narrowing, claim-constant helper, SessionExpiry tests

src/ScadaLink.CentralUI/Components/Pages/Design/SharedScriptForm.razor

@@ -172,11 +172,10 @@
     private ScriptAnalysis.SandboxRunResult? _runResult;
     private CancellationTokenSource? _runCts;
 
-    private async Task<string> GetCurrentUserAsync()
-    {
-        var authState = await AuthStateProvider.GetAuthenticationStateAsync();
-        return authState.User.FindFirst("Username")?.Value ?? "unknown";
-    }
+    // CentralUI-024: delegates to the shared helper so the claim type stays
+    // resolved through JwtTokenService rather than a duplicated magic string.
+    private Task<string> GetCurrentUserAsync()
+        => AuthStateProvider.GetCurrentUsernameAsync();
 
     protected override async Task OnInitializedAsync()
     {

src/ScadaLink.CentralUI/Components/Pages/Design/SharedScripts.razor

@@ -101,11 +101,10 @@
 </div>
 
 @code {
-    private async Task<string> GetCurrentUserAsync()
-    {
-        var authState = await AuthStateProvider.GetAuthenticationStateAsync();
-        return authState.User.FindFirst("Username")?.Value ?? "unknown";
-    }
+    // CentralUI-024: delegates to the shared helper so the claim type stays
+    // resolved through JwtTokenService rather than a duplicated magic string.
+    private Task<string> GetCurrentUserAsync()
+        => AuthStateProvider.GetCurrentUsernameAsync();
 
     private List<SharedScript> _scripts = new();
     private bool _loading = true;

src/ScadaLink.CentralUI/Components/Pages/Design/TemplateCreate.razor

@@ -119,9 +119,8 @@
         NavigationManager.NavigateTo("/design/templates");
     }
 
-    private async Task<string> GetCurrentUserAsync()
-    {
-        var authState = await AuthStateProvider.GetAuthenticationStateAsync();
-        return authState.User.FindFirst("Username")?.Value ?? "unknown";
-    }
+    // CentralUI-024: delegates to the shared helper so the claim type stays
+    // resolved through JwtTokenService rather than a duplicated magic string.
+    private Task<string> GetCurrentUserAsync()
+        => AuthStateProvider.GetCurrentUsernameAsync();
 }

src/ScadaLink.CentralUI/Components/Pages/Design/TemplateEdit.razor

@@ -218,11 +218,10 @@
         NavigationManager.NavigateTo("/design/templates");
     }
 
-    private async Task<string> GetCurrentUserAsync()
-    {
-        var authState = await AuthStateProvider.GetAuthenticationStateAsync();
-        return authState.User.FindFirst("Username")?.Value ?? "unknown";
-    }
+    // CentralUI-024: delegates to the shared helper so the claim type stays
+    // resolved through JwtTokenService rather than a duplicated magic string.
+    private Task<string> GetCurrentUserAsync()
+        => AuthStateProvider.GetCurrentUsernameAsync();
 
     private RenderFragment RenderTemplateDetail() => __builder =>
     {

src/ScadaLink.CentralUI/Components/Pages/Design/Templates.razor

@@ -99,11 +99,10 @@
 </div>
 
 @code {
-    private async Task<string> GetCurrentUserAsync()
-    {
-        var authState = await AuthStateProvider.GetAuthenticationStateAsync();
-        return authState.User.FindFirst("Username")?.Value ?? "unknown";
-    }
+    // CentralUI-024: delegates to the shared helper so the claim type stays
+    // resolved through JwtTokenService rather than a duplicated magic string.
+    private Task<string> GetCurrentUserAsync()
+        => AuthStateProvider.GetCurrentUsernameAsync();
 
     private List<Template> _templates = new();
     private List<TemplateFolder> _folders = new();