Remove target='_blank' for single-page login experience

- Remove target='_blank' from login button
- Remove auto-refresh JavaScript
- Keep the critical SameSite=None session fix for iframe compatibility
- User preference: login in same page instead of new tab

backend/routers/auth.py

@@ -338,32 +338,12 @@ async def login_page(request: Request):
             </div>
             
                 <p>Please log in with your Hugging Face account to continue.</p>
-                <a href="/auth/login" class="login-btn" target="_blank">🚀 Login with Hugging Face</a>
-                
-                <p style="margin-top: 20px; font-size: 12px; color: #666;">
-                    <strong>Note:</strong> The login will open in a new tab. After logging in, please close the tab and refresh this page.
-                </p>
+                <a href="/auth/login" class="login-btn">🚀 Login with Hugging Face</a>
             
             <p style="margin-top: 30px; font-size: 12px; color: #888;">
                 By logging in, you agree to use this service responsibly and in accordance with our usage policies.
             </p>
         </div>
-        
-        <script>
-        // Check for login status every 3 seconds
-        setInterval(async function() {
-            try {
-                const response = await fetch('/auth/status');
-                const data = await response.json();
-                if (data.user_authenticated) {
-                    // User is logged in, redirect to main app
-                    window.location.href = '/';
-                }
-            } catch (error) {
-                console.log('Checking login status...');
-            }
-        }, 3000);
-        </script>
     </body>
     </html>
     """