Exact / Bouw7 Booking Integration

Booking material lines into an external ERP is a money path: the network write can fail after some lines are already booked, and a naive retry would book them again. The flow has to stay correct under partial failure and safe to roll out without ever touching real bookings by accident.

• Live in production at a client, after being verified end to end against the Exact sandbox first
• A retry after a partial failure never double-books a material line
• Replaced an error-prone manual ERP entry step with a one-click, auditable booking

• Idempotent booking via a per-line marker, so a retry skips lines already sent
• Resumable after a partial failure: on error it stops, holds the project in 'Ready for Exact', and reports 'X of Y lines booked'
• The external ERP call is kept outside the database transaction, so a failed send never leaves a half-committed local state
• A confirm-lock that blocks a double confirm, so the same project cannot be booked twice at once
• A runtime three-state switch (off / dry-run / live): dry-run logs the exact payload without booking, and the flag defaults to off
• Push, idempotency, partial-failure, and dry-run paths covered test-first