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- Deleted several outdated scripts: `create_test_users.py`, `test_image_write_access.py`, `update_free_plan.py`, and the database file `db.sqlite3` to clean up the backend.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/blocks/index.ts

@@ -0,0 +1,8 @@
+export { HeroBlock } from './HeroBlock';
+export type { HeroBlockProps } from './HeroBlock';
+export { FeatureGridBlock } from './FeatureGridBlock';
+export type { FeatureGridBlockProps } from './FeatureGridBlock';
+export { StatsPanel } from './StatsPanel';
+export type { StatsPanelProps, StatItem } from './StatsPanel';
+
+