Header model replacing mrp.production. mail.thread for chatter,
priority/state/deadline tracking, sequence WH/JOB/00001+. Tests
cover create, confirm, cancel, and forbidden double-confirm.
State machine:
draft -> confirmed -> in_progress -> done
v ^
cancelled (rework reverts here)
on_hold can be entered from confirmed or in_progress.
Step relations come in Task 1.5; SO/recipe/portal/cost extension
fields come in Task 1.4.
Part of: native job model migration (spec 2026-04-25)
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>