Runtime Phases

RETL runs declarations through four durable phases.

Phase	Purpose
collect	Read source rows through the selected backend.
stage	Convert rows into canonical State or Event records.
reconcile	Compare staged intent with durable runtime state and produce work.
sync	Submit destination-facing work and record delivery outcomes.

The phases are evidence boundaries. Failures should leave enough runtime state to retry or inspect the run without guessing what happened.

Dry runs execute planning paths without irreversible destination writes or destination progress advancement.