fix(e2e): activate e2e profile in dev mode and create reader user idempotently

- Add e2e to the dev Maven profile's spring.profiles.active so
  DataInitializer always runs when developing/testing locally
- Create the reader test user independently of the person-seed guard
  so it survives restarts where seed data already exists
- Set SPRING_PROFILES_ACTIVE=dev,e2e in docker-compose backend service

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docker-compose.yml

@@ -98,6 +98,7 @@ services:
       S3_SECRET_KEY: ${MINIO_ROOT_PASSWORD}
       S3_BUCKET_NAME: ${MINIO_DEFAULT_BUCKETS}
       S3_REGION: us-east-1
+      SPRING_PROFILES_ACTIVE: dev,e2e
       APP_BASE_URL: ${APP_BASE_URL:-http://localhost:3000}
       # Defaults to the local Mailpit catcher — override in .env for production SMTP
       MAIL_HOST: ${MAIL_HOST:-mailpit}