feat(hooks): add migration automation, deactivated site guard, and super admin flag

- Run database migrations on startup if `RUN_MIGRATIONS=true`
- Block public access to deactivated sites with a 503 page, allowing admin/login paths
- Add `isSuperAdmin` boolean to session user type in app.d.ts

docker-compose.yml

@@ -0,0 +1,16 @@
+version: '3.8'
+services:
+  postgres:
+    image: postgres:16-alpine
+    container_name: collective-hub-db
+    environment:
+      POSTGRES_USER: hub_dev
+      POSTGRES_PASSWORD: hub_dev_password
+      POSTGRES_DB: collective_hub
+    ports:
+      - '5432:5432'
+    volumes:
+      - pgdata:/var/lib/postgresql/data
+
+volumes:
+  pgdata: