Settings display demo and login fix (#4884)

# Description of Changes
<img width="1569" height="980" alt="image"
src="https://github.com/user-attachments/assets/dca1c227-ed84-4393-97a1-e3ce6eb1620b"
/>

<img width="1596" height="935" alt="image"
src="https://github.com/user-attachments/assets/2003e1be-034a-4cbb-869e-6d5d912ab61d"
/>

<img width="1543" height="997" alt="image"
src="https://github.com/user-attachments/assets/fe0c4f4b-eeee-4db4-a041-e554f350255a"
/>


---

## Checklist

### General

- [ ] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ ] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md)
(if applicable)
- [ ] I have performed a self-review of my own code
- [ ] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### Translations (if applicable)

- [ ] I ran
[`scripts/counter_translation.py`](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/docs/counter_translation.md)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md#6-testing)
for more details.

frontend/src/core/services/httpErrorHandler.ts

@@ -92,6 +92,32 @@ export async function handleHttpError(error: any): Promise<boolean> {
   if (error?.config?.suppressErrorToast === true) {
     return false; // Don't show global toast, but continue rejection
   }
+
+  // Handle 401 authentication errors
+  const status: number | undefined = error?.response?.status;
+  if (status === 401) {
+    const pathname = window.location.pathname;
+
+    // Check if we're already on an auth page
+    const isAuthPage = pathname.includes('/login') ||
+                      pathname.includes('/signup') ||
+                      pathname.includes('/auth/') ||
+                      pathname.includes('/invite/');
+
+    // If not on auth page, redirect to login with expired session message
+    if (!isAuthPage) {
+      console.debug('[httpErrorHandler] 401 detected, redirecting to login');
+      // Store the current location so we can redirect back after login
+      const currentLocation = window.location.pathname + window.location.search;
+      // Redirect to login with state
+      window.location.href = `/login?expired=true&from=${encodeURIComponent(currentLocation)}`;
+      return true; // Suppress toast since we're redirecting
+    }
+
+    // On auth pages, suppress the toast (user is already trying to authenticate)
+    console.debug('[httpErrorHandler] Suppressing 401 on auth page:', pathname);
+    return true;
+  }
   // Compute title/body (friendly) from the error object
   const { title, body } = extractAxiosErrorMessage(error);
 
@@ -112,7 +138,6 @@ export async function handleHttpError(error: any): Promise<boolean> {
 
   // 2) Generic-vs-special dedupe by endpoint
   const url: string | undefined = error?.config?.url;
-  const status: number | undefined = error?.response?.status;
   const now = Date.now();
   const isSpecial =
     status === 422 ||