Fix OAuth loading indicator to persist during callback processing

- Show loading indicator immediately when page loads with OAuth code
- Maintain loading state throughout OAuth callback processing
- Prevents confusing UX where button reappears without feedback
- Loading indicator now visible from click through authentication completion

CHANGELOG.md

@@ -52,7 +52,9 @@
 ### Added
 - **OAuth Loading Indicator**
   - Added loading spinner under sign in button during OAuth redirect
-  - Shows "Redirecting to Hugging Face..." message
+  - Shows "Redirecting to Hugging Face..." message during entire OAuth flow
+  - Loading indicator persists during OAuth callback processing
+  - Shows immediately when returning from HuggingFace with auth code
   - Button disables during redirect to prevent double-clicks
   - Uses Bootstrap spinner for consistent styling
 

ui.R

@@ -1552,6 +1552,16 @@ ui <- navbarPage(
     tags$script(
       HTML(
         "
+    // Check for OAuth code on page load (before Shiny connects)
+    $(document).ready(function() {
+      var urlParams = new URLSearchParams(window.location.search);
+      if (urlParams.has('code')) {
+        // Show loading indicator immediately
+        $('#authLoadingIndicator').show();
+        $('#hfSignInBtn').prop('disabled', true);
+      }
+    });
+
     // Check authentication state and show/hide overlay
     Shiny.addCustomMessageHandler('auth_state', function(message) {
       var overlay = document.getElementById('authOverlay');
@@ -1567,6 +1577,9 @@ ui <- navbarPage(
       var urlParams = new URLSearchParams(window.location.search);
       if (urlParams.has('code')) {
         console.log('OAuth code found in URL, sending to Shiny');
+        // Show loading indicator during OAuth processing
+        $('#authLoadingIndicator').show();
+        $('#hfSignInBtn').prop('disabled', true);
         var code = urlParams.get('code');
         Shiny.setInputValue('oauth_code', code, {priority: 'event'});
         // Clean URL