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/settings/storage.py

@@ -0,0 +1,124 @@
+"""
+Storage configuration for thrillwiki project.
+
+This module configures static files, media files, and storage backends
+including WhiteNoise for static file serving.
+
+Why python-decouple?
+- Already used in base.py for consistency
+- Simpler API than django-environ
+- Sufficient for our configuration needs
+- Better separation of config from code
+"""
+
+from pathlib import Path
+from decouple import config
+
+# =============================================================================
+# Base Directory
+# =============================================================================
+# This will be set by the importing module, but we define a fallback
+BASE_DIR = Path(__file__).resolve().parent.parent.parent
+
+# =============================================================================
+# Static Files Configuration
+# =============================================================================
+# https://docs.djangoproject.com/en/5.0/howto/static-files/
+
+STATIC_URL = config("STATIC_URL", default="static/")
+STATICFILES_DIRS = [BASE_DIR / "static"]
+STATIC_ROOT = BASE_DIR / "staticfiles"
+
+# =============================================================================
+# WhiteNoise Configuration
+# =============================================================================
+# https://whitenoise.readthedocs.io/
+# WhiteNoise serves static files efficiently without a separate web server
+
+# Compression quality for Brotli/Gzip (1-100, higher = better but slower)
+WHITENOISE_COMPRESSION_QUALITY = config(
+    "WHITENOISE_COMPRESSION_QUALITY", default=90, cast=int
+)
+
+# Cache max-age for static files (1 year for immutable content)
+WHITENOISE_MAX_AGE = config(
+    "WHITENOISE_MAX_AGE", default=31536000, cast=int
+)
+
+# Don't fail on missing manifest entries (graceful degradation)
+WHITENOISE_MANIFEST_STRICT = config(
+    "WHITENOISE_MANIFEST_STRICT", default=False, cast=bool
+)
+
+# Additional MIME types
+WHITENOISE_MIMETYPES = {
+    ".webp": "image/webp",
+    ".woff2": "font/woff2",
+}
+
+# Skip compressing already compressed formats
+WHITENOISE_SKIP_COMPRESS_EXTENSIONS = [
+    "jpg", "jpeg", "png", "gif", "webp",  # Images
+    "zip", "gz", "tgz", "bz2", "tbz", "xz", "br",  # Archives
+    "swf", "flv",  # Flash
+    "woff", "woff2",  # Fonts
+    "mp3", "mp4", "ogg", "webm",  # Media
+]
+
+# =============================================================================
+# Media Files Configuration
+# =============================================================================
+# User-uploaded content
+
+MEDIA_URL = config("MEDIA_URL", default="/media/")
+MEDIA_ROOT = BASE_DIR.parent / "shared" / "media"
+
+# =============================================================================
+# Storage Backends Configuration
+# =============================================================================
+# Django 4.2+ storage configuration
+
+STORAGES = {
+    # Default storage for user uploads (FileField, ImageField)
+    "default": {
+        "BACKEND": "django.core.files.storage.FileSystemStorage",
+        "OPTIONS": {
+            "location": str(MEDIA_ROOT),
+        },
+    },
+    # Static files storage
+    "staticfiles": {
+        "BACKEND": "django.contrib.staticfiles.storage.StaticFilesStorage",
+        "OPTIONS": {
+            "location": str(STATIC_ROOT),
+        },
+    },
+}
+
+# =============================================================================
+# File Upload Security Settings
+# =============================================================================
+# These settings help prevent denial-of-service attacks via file uploads
+
+# Maximum size (in bytes) of file to upload into memory (2.5MB)
+# Files larger than this are written to disk
+FILE_UPLOAD_MAX_MEMORY_SIZE = config(
+    "FILE_UPLOAD_MAX_MEMORY_SIZE", default=2621440, cast=int
+)
+
+# Maximum size (in bytes) of request data (10MB)
+# This limits the total size of POST request body
+DATA_UPLOAD_MAX_MEMORY_SIZE = config(
+    "DATA_UPLOAD_MAX_MEMORY_SIZE", default=10485760, cast=int
+)
+
+# Maximum number of GET/POST parameters (1000)
+DATA_UPLOAD_MAX_NUMBER_FIELDS = config(
+    "DATA_UPLOAD_MAX_NUMBER_FIELDS", default=1000, cast=int
+)
+
+# File upload permissions (0o644 = rw-r--r--)
+FILE_UPLOAD_PERMISSIONS = 0o644
+
+# Directory permissions for uploaded files (0o755 = rwxr-xr-x)
+FILE_UPLOAD_DIRECTORY_PERMISSIONS = 0o755