🐛(frontend) conditionally render AI button in toolbar

Added a feature flag check to ensure the AIGroupButton is only rendered
when AI_FEATURE_ENABLED is explicitly set to "true". This prevents the
AI button from appearing when the feature is not configured or disabled.

Fixes #782

Signed-off-by: Matthias <matthias@universum.com>

src/backend/core/api/viewsets.py

@@ -1684,6 +1684,7 @@ class ConfigView(drf.views.APIView):
             Return a dictionary of public settings.
         """
         array_settings = [
+            "AI_FEATURE_ENABLED",
             "COLLABORATION_WS_URL",
             "CRISP_WEBSITE_ID",
             "ENVIRONMENT",