Fix data exporting (#61)

* give the worker process access to rails storage

* add db dependence on worker on our compose example file

compose.example.yml

@@ -65,8 +65,12 @@ services:
   worker:
     image: ghcr.io/we-promise/sure:latest
     command: bundle exec sidekiq
+    volumes:
+      - app-storage:/rails/storage
     restart: unless-stopped
     depends_on:
+      db:
+        condition: service_healthy
       redis:
         condition: service_healthy
     environment: