feat(jobs): button_start auto-routes contract_review steps to QA-005

User feedback on WH/JOB/00341 (S00279 retest): clicking Start on
the Contract Review step changed state to in_progress but didn't
take them to QA-005. They had to then click Finish & Next twice
to land on the form — confusing flow.

Better UX: when an operator clicks Start on a step where
recipe_node.default_kind='contract_review', the step starts AND
the QA-005 form opens immediately. Operator signs/dismisses,
navigates back, hits Finish & Next once → step finishes + advances.

Implementation:
  fp.job.step.button_start, after super() returns and the
  receiving check runs, calls _fp_contract_review_redirect()
  (existing helper). If it returns an action, return that
  instead of the parent's result. Single-record only — bulk
  button_start (job-level start-all) shouldn't navigate.

Helper logic unchanged — same gate matrix:
  * recipe_node.default_kind == 'contract_review'
  * job has part_catalog_id
  * review state NOT in (complete, dismissed)

When review is already complete, the gate clears: button_start
returns the normal True so the operator can advance the step
without bouncing through QA-005 again.

Tests:
  test_button_start_routes_cr_step_to_qa005 — start opens QA-005
  test_button_start_does_not_route_when_review_complete — start
    does NOT redirect once review is signed off

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

fusion_plating/fusion_plating_jobs/models/fp_job_step.py

@@ -148,6 +148,20 @@ class FpJobStep(models.Model):
                     'so': so.name or '',
                     'status': recv or 'unknown',
                 })
+
+        # Sub 12e v4 — when an operator starts a contract_review step,
+        # immediately route to the QA-005 form. The step stays
+        # in_progress in the background; the operator signs (or
+        # dismisses) the review on QA-005, navigates back to the job,
+        # then clicks Finish & Next to advance. This removes the
+        # earlier "click Start, then click Finish & Next, then maybe
+        # click Finish & Next again" friction.
+        # Single-record only — multi-record button_start (e.g. job
+        # bulk-start) shouldn't navigate.
+        if len(self) == 1:
+            cr_action = self._fp_contract_review_redirect()
+            if cr_action:
+                return cr_action
         return result
 
     def button_pause(self):