Add site builder service to Docker Compose and remove obsolete scripts

- Introduced a new service `igny8_site_builder` in `docker-compose.app.yml` for site building functionality, including environment variables and volume mappings.
- Deleted several outdated scripts: `create_test_users.py`, `test_image_write_access.py`, `update_free_plan.py`, and the database file `db.sqlite3` to clean up the backend.
- Updated Django settings and URL configurations to integrate the new site builder module.

frontend/src/components/shared/layouts/DefaultLayout.tsx

@@ -0,0 +1,28 @@
+import type { ReactNode } from 'react';
+import './layouts.css';
+
+export interface DefaultLayoutProps {
+  hero?: ReactNode;
+  sections: ReactNode[];
+  sidebar?: ReactNode;
+}
+
+export function DefaultLayout({ hero, sections, sidebar }: DefaultLayoutProps) {
+  return (
+    <div className="shared-layout">
+      {hero && <div className="shared-layout__hero">{hero}</div>}
+      <div className="shared-layout__body">
+        <div className="shared-layout__main">
+          {sections.map((section, index) => (
+            <div key={index} className="shared-layout__section">
+              {section}
+            </div>
+          ))}
+        </div>
+        {sidebar && <aside className="shared-layout__sidebar">{sidebar}</aside>}
+      </div>
+    </div>
+  );
+}
+
+