feat(jobs): Phase 4 light refactors — notifications, KPI source tag

- Adds 'job_confirmed' and 'job_complete' trigger events to
  fp.notification.template (legacy 'mo_confirmed' / 'mo_complete'
  stay for bridge_mrp).
- fp.job.action_confirm and button_mark_done now fire those
  notifications best-effort via fp.notification.template._dispatch
  (silent skip if templates absent or notifications module missing).
- Adds x_fc_source ['mrp', 'jobs'] tag to fusion.plating.kpi.value
  so Phase 9 dashboards can filter or display both sources.
- Verified aerospace/nuclear/cgp/safety modules don't directly
  reference mrp.production or mrp.workorder.

Configurator integration was already covered by Task 2.5's SO
confirm hook (reads x_fc_part_catalog_id and x_fc_coating_config_id
from sale.order.line).

Manifest 19.0.1.6.0 -> 19.0.1.7.0.

Part of: native job model migration (spec 2026-04-25)
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

fusion_plating/fusion_plating_jobs/models/__init__.py

@@ -19,3 +19,7 @@ from . import fp_certificate
 from . import fp_thickness_reading
 from . import fp_delivery
 from . import fp_racking_inspection
+
+# Phase 4 — light refactors batch B (notifications, KPI source tag).
+from . import fp_notification_trigger
+from . import fusion_plating_kpi_value