Review and safely merge duplicate customers

WaterMark detects likely duplicate customer records, previews every dependent record and credit dollar, and supports a bounded undo without overwriting later activity.

Where: Customers -> Review duplicates

1. Open Review duplicates and select one suggested customer pair.
2. Read the merge preview, including invoices, jobs, pools, messages, contacts, and customer credit that will move.
3. Choose which conflicting field value survives, then confirm the merge once.
4. Use Undo only when needed; WaterMark moves back the rows captured at merge time and leaves later customer activity on the survivor.