feat: Implement Phase 2 cross-cutting services with email and notification enhancements

- Refactor email verification and password reset utilities to use new email service.
- Introduce email delivery queue and notification delivery model for better tracking.
- Enhance file validation and storage services for improved security and ownership management.
- Add cron job for cleaning inactive notifications with retention policy.
- Update document worker to handle document generation and storage more efficiently.
- Implement logging improvements in activity and log workers.
- Create comprehensive documentation for new API endpoints and services.
- Add unit tests for file validation and notification policies to ensure robustness.

.env.sample

@@ -52,6 +52,16 @@ AWS_ACCESS_KEY_ID=
 AWS_SECRET_ACCESS_KEY=
 AWS_REGION=
 AWS_S3_BUCKET_NAME=
+S3_ENDPOINT=
+S3_FORCE_PATH_STYLE=false
+S3_SIGNED_URL_TTL_SECONDS=900
+S3_MAX_UPLOAD_BYTES=5242880
+
+# Cross-cutting worker and retention settings
+EMAIL_QUEUE_CONCURRENCY=5
+DOCUMENT_QUEUE_CONCURRENCY=2
+NOTIFICATION_RETENTION_DAYS=90
+LOG_RETENTION_DAYS=30
 
 # Optional documentation login
 DOCS_USER=