Implement 30-day database backup retention

[rjan90]

Done Criteria

• Automated database backups retain 30 days of history
• Restores from backups within that 30-day window are verified to work
• Team documentation reflects the 30-day retention policy

Why Important

Issue #68 intentionally delivers 7-day retention for GA. This follow-up tracks the post-GA (M4.5) work to extend retention to 30 days so #68 can close once its remaining GA criteria are met.

User/Customer

Dealbot operators

Notes

• Follow-up to Set up 7 day database backups #68