Add secret management guide, client-side performance monitoring, and search accessibility enhancements

- Introduced a comprehensive Secret Management Guide detailing best practices, secret classification, development setup, production management, rotation procedures, and emergency protocols.
- Implemented a client-side performance monitoring script to track various metrics including page load performance, paint metrics, layout shifts, and memory usage.
- Enhanced search accessibility with keyboard navigation support for search results, ensuring compliance with WCAG standards and improving user experience.

backend/config/celery.py

@@ -6,18 +6,25 @@ This module sets up Celery for background task processing including:
 - Cache warming
 - Analytics processing
 - Email notifications
+
+Celery uses the same Django settings module as the main application,
+which can be configured via DJANGO_SETTINGS_MODULE environment variable.
 """
 
 import os
 from celery import Celery
+from decouple import config
 
-# Set the default Django settings module for the 'celery' program.
-os.environ.setdefault("DJANGO_SETTINGS_MODULE", "config.django.local")
+# Use the same Django settings module as the main application
+# Default to production (matching WSGI/ASGI), can be overridden via environment
+# Honor existing DJANGO_SETTINGS_MODULE if already set
+if "DJANGO_SETTINGS_MODULE" not in os.environ:
+    os.environ["DJANGO_SETTINGS_MODULE"] = "config.django.production"
 
 app = Celery("thrillwiki")
 
 # Get Redis URL from environment variable with fallback
-REDIS_URL = os.environ.get("REDIS_URL", "redis://localhost:6379/1")
+REDIS_URL = config("REDIS_URL", default="redis://localhost:6379/1")
 
 # Celery Configuration - set directly without loading from Django settings first
 app.conf.update(