Enhance public access and error handling in site-related views and loaders

- Updated `DebugScopedRateThrottle` to allow public access for blueprint list requests with site filters.
- Modified `SiteViewSet` and `SiteBlueprintViewSet` to permit public read access for list requests.
- Enhanced `loadSiteDefinition` to resolve site slugs to IDs, improving the loading process for site definitions.
- Improved error handling in `SiteDefinitionView` and `loadSiteDefinition` for better user feedback.
- Adjusted CSS styles for better layout and alignment in shared components.

backend/igny8_core/auth/views.py

@@ -478,16 +478,26 @@ class SiteViewSet(AccountModelViewSet):
     
     def get_permissions(self):
         """Allow normal users (viewer) to create sites, but require editor+ for other operations."""
+        # Allow public read access for list requests with slug filter (used by Sites Renderer)
+        if self.action == 'list' and self.request.query_params.get('slug'):
+            from rest_framework.permissions import AllowAny
+            return [AllowAny()]
         if self.action == 'create':
             return [permissions.IsAuthenticated()]
         return [IsEditorOrAbove()]
     
     def get_queryset(self):
         """Return sites accessible to the current user."""
-        user = self.request.user
-        if not user or not user.is_authenticated:
+        # If this is a public request (no auth) with slug filter, return site by slug
+        if not self.request.user or not self.request.user.is_authenticated:
+            slug = self.request.query_params.get('slug')
+            if slug:
+                # Return queryset directly from model (bypassing base class account filtering)
+                return Site.objects.filter(slug=slug, is_active=True)
             return Site.objects.none()
         
+        user = self.request.user
+        
         # ADMIN/DEV OVERRIDE: Both admins and developers can see all sites
         if user.is_admin_or_developer():
             return Site.objects.all().distinct()