feat(jobs): order-level ship-readiness helpers

_fp_order_ship_state + _fp_mark_order_shipped enforce spec D4 ship-together:
the order ships only when every active job on it is awaiting_ship/done.
Shared by the tablet shipping endpoints and /fp/workspace/load.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

fusion_plating/fusion_plating_jobs/tests/__init__.py

@@ -9,3 +9,4 @@ from . import test_active_step_id
 from . import test_autopause_cron
 from . import test_post_shop_states
 from . import test_recipe_cert_suppression
+from . import test_order_ship_state