Filter demo-data plugins from production settings

mandelstudio/settings/base.py

@@ -27,6 +27,14 @@ INSTALLED_APPS = [
     "mandelstudio",
 ] + INSTALLED_APPS
 
+# Never allow demo-data plugins in this production project context.
+def _is_demo_data_app(app_label: str) -> bool:
+    normalized = "".join(ch for ch in app_label.lower() if ch.isalnum())
+    return "demodata" in normalized
+
+
+INSTALLED_APPS = [app for app in INSTALLED_APPS if not _is_demo_data_app(app)]
+
 # Route through the project URL layer so MandelStudio can override
 # sitemap/robots behavior while still delegating the main Ocyan routes.
 ROOT_URLCONF = "mandelstudio.urls"