Duckbill™ migration plan

Migration is a triage page at /inbox/migration. It builds a plan from folder scans already stored for connected Gmail and iCloud accounts. The target service is Microsoft.

The page lists those sources when they are connected. A mailbox with no folder scan stays on the page and shows an empty state. Creating a plan does not call Gmail, iCloud, or Microsoft.

POST /api/migrations/plans writes one inbox_agent.migration_plans row per inventoried source. Each row keeps dry_run_required true and source_delete_allowed false. A later create for the same mailbox reopens that plan. iCloud stays read-write. This page does not move or delete mail.

Signed-in path: https://duckbill-dev.jasonkoch.io/inbox/migration