feat(plating): hard-required fields on WO start — operator + bath + tank

User audit caught: in the workforce E2E run we had no idea which bath /
which tank ran the job. For aerospace traceability that's a deal-
breaker. Add a validation gate on mrp.workorder.button_start so
operators can't tap START without the data the shop floor MUST capture.

**Three new pieces on mrp.workorder:**

1. `_fp_is_wet_process()` — best-effort "does this WO involve a
   chemistry bath?" check. Three signals in priority order:
   a. A bath is already linked → definitely wet
   b. The workcenter's FP work-centre supports a wet process family
      (plating, pre/post-treatment, strip, passivation)
   c. WO name contains a wet-process keyword (plat, nickel, chrome,
      anodiz, zinc, etch, clean, rinse, strip, passivat, electroless…)
   The keyword fallback is needed because most existing recipes have
   no process_type_id set on their operation nodes.

2. `_fp_check_required_fields_before_start()` — runs before the
   existing certification check. Rules:
   • Every WO needs an assigned operator (x_fc_assigned_user_id).
     Without it, productivity records can't be attributed and the
     proficiency tracker has no employee to credit.
   • Wet WOs additionally need x_fc_bath_id + x_fc_tank_id. So we
     know exactly which chemistry bath ran the job and which physical
     tank it sat in.
   Raises a clear UserError listing the missing fields if any.

3. `x_fc_requires_bath` (compute, non-stored) — surfaces the wet check
   to the form view so bath + tank fields render with `required=`.

**View changes:**
- `x_fc_assigned_user_id` is now `required="1"` on the form
- `x_fc_bath_id` + `x_fc_tank_id` use `required="x_fc_requires_bath"`
  → red asterisk only when the WO is actually wet

**Simulator updates** (scripts/fp_e2e_workforce.py):
- Hannah now explicitly assigns bath + tank to wet WOs during planning,
  AND pre-issues operator certifications for the bath's process type
  (real shop manager workflow).
- Two negative tests added that PROVE the gates fire:
  • Test 1: strip the operator → button_start raises "missing Assigned Operator"
  • Test 2: strip bath/tank on a wet WO → button_start raises "missing Bath/Tank"

**Final E2E:** 42 PASS / 2 WARN / 0 FAIL out of 44 checks.
Both remaining WARNs (bake-window auto-create, first-piece gate) are
expected behaviour — those are coating-driven and the test coating
intentionally doesn't trigger them.

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

fusion_plating/scripts/fp_audit_workorders.py

@@ -0,0 +1,11 @@
+env = env  # noqa
+recipe = env['fusion.plating.process.node'].search(
+    [('node_type', '=', 'recipe'), ('name', '=', 'ENP-ALUM-BASIC')], limit=1)
+print(f'Recipe: {recipe.name}')
+def walk(node, indent=0):
+    pt = node.process_type_id.process_family if node.process_type_id else '(none)'
+    wc = node.work_center_id.name if node.work_center_id else '(none)'
+    print(f'{"  "*indent}- [{node.node_type:9}] {node.name!r:35} pt_family={pt!r:18} wc={wc}')
+    for c in node.child_ids.sorted('sequence'):
+        walk(c, indent+1)
+walk(recipe)

fusion_plating/scripts/fp_e2e_workforce.py

@@ -223,7 +223,39 @@ WO_OPERATORS = {
 }
 
 step('HANNAH', 'Assigns each WO to a specific operator')
+# Pick a bath + a tank for any WO that needs wet-process traceability
+test_bath = env['fusion.plating.bath'].search([], limit=1)
+test_tank = env['fusion.plating.tank'].search([], limit=1)
+
+# Issue operator certifications for the bath's process type so the cert
+# gate doesn't block legitimate operators (in real life the manager
+# tracks training + issues certs; for a clean E2E we pre-issue).
+Cert = env.get('fp.operator.certification')
+if Cert is not None and test_bath and test_bath.process_type_id:
+    pt = test_bath.process_type_id
+    for op_key in ('john', 'maria', 'tom', 'ana', 'frank'):
+        emp = env['hr.employee'].search(
+            [('user_id', '=', users[op_key].id)], limit=1)
+        if not emp:
+            continue
+        existing = Cert.sudo().search([
+            ('employee_id', '=', emp.id),
+            ('process_type_id', '=', pt.id),
+            ('revoked', '=', False),
+        ], limit=1)
+        if not existing:
+            Cert.sudo().create({
+                'employee_id': emp.id,
+                'process_type_id': pt.id,
+                'issued_by_id': users['hannah'].id,
+                'notes': 'Auto-issued for E2E workforce simulation',
+            })
+    show('  certifications', f'pre-issued for {pt.name} → 5 operators')
+show('  test bath', f'{test_bath.name}' if test_bath else '(none — wet-WO assignment will fail)')
+show('  test tank', f'{test_tank.name}' if test_tank else '(none — wet-WO assignment will fail)')
+
 assignments = []
+wet_assignments = []
 for wo in mo.workorder_ids:
     name_l = (wo.name or '').lower()
     operator_key = None
@@ -231,16 +263,79 @@ for wo in mo.workorder_ids:
         if kw in name_l:
             operator_key = k
             break
-    operator_key = operator_key or 'john'  # fallback
+    operator_key = operator_key or 'john'
     op_user = users[operator_key]
     wo.sudo().x_fc_assigned_user_id = op_user.id
+
+    # If this is a wet-process WO (E-Nickel Plating, etch, rinse, etc.)
+    # Hannah must also pin the exact bath + tank for traceability.
+    is_wet = wo._fp_is_wet_process() if hasattr(wo, '_fp_is_wet_process') else False
+    bath_assigned = tank_assigned = False
+    if is_wet and test_bath and test_tank:
+        wo.sudo().write({
+            'x_fc_bath_id': test_bath.id,
+            'x_fc_tank_id': test_tank.id,
+        })
+        bath_assigned = True
+        tank_assigned = True
+        wet_assignments.append(wo)
+
     assignments.append((wo, op_user, operator_key))
-    show(f'  WO {wo.id}', f'"{wo.name}" → {op_user.name}')
+    extras = ''
+    if is_wet:
+        extras = f'  [WET — bath={test_bath.name if bath_assigned else "MISSING"}, tank={test_tank.name if tank_assigned else "MISSING"}]'
+    show(f'  WO {wo.id}', f'"{wo.name}" → {op_user.name}{extras}')
 
 assigned_count = sum(1 for w, _, _ in assignments if w.x_fc_assigned_user_id)
 finding('PASS' if assigned_count == n_wos else 'FAIL',
         'WO assignment', f'{assigned_count}/{n_wos} have x_fc_assigned_user_id')
 
+wet_with_bath = sum(1 for w in wet_assignments if w.x_fc_bath_id and w.x_fc_tank_id)
+finding('PASS' if (not wet_assignments) or (wet_with_bath == len(wet_assignments)) else 'FAIL',
+        'wet-WO bath+tank set',
+        f'{wet_with_bath}/{len(wet_assignments)} wet WOs have both bath + tank')
+
+# ===== Negative tests: validation MUST block bad starts =====
+banner('PHASE 4b — Negative tests: validation gates fire correctly')
+
+# Test 1: try to start a WO with operator stripped → expect UserError
+step('SYSTEM', 'Test 1 — un-assigning operator and trying to start')
+test_wo = mo.workorder_ids[0]
+saved_op = test_wo.x_fc_assigned_user_id.id
+test_wo.sudo().x_fc_assigned_user_id = False
+gate_fired = False
+try:
+    test_wo.sudo().button_start()
+except Exception as e:
+    gate_fired = 'Assigned Operator' in str(e) or 'required' in str(e).lower()
+    show('  blocked with', str(e).splitlines()[0][:120])
+finding('PASS' if gate_fired else 'FAIL',
+        'gate: missing operator',
+        'blocked' if gate_fired else 'NOT blocked — validation broken')
+test_wo.sudo().x_fc_assigned_user_id = saved_op
+
+# Test 2: try to start a WET WO without bath/tank → expect UserError
+if wet_assignments:
+    step('SYSTEM', 'Test 2 — wet WO with bath/tank stripped')
+    wet_wo = wet_assignments[0]
+    saved_bath = wet_wo.x_fc_bath_id.id
+    saved_tank = wet_wo.x_fc_tank_id.id
+    wet_wo.sudo().write({'x_fc_bath_id': False, 'x_fc_tank_id': False})
+    gate_fired = False
+    try:
+        wet_wo.sudo().button_start()
+    except Exception as e:
+        msg = str(e)
+        gate_fired = ('Bath' in msg and 'Tank' in msg) or 'required' in msg.lower()
+        show('  blocked with', msg.splitlines()[0][:120])
+    finding('PASS' if gate_fired else 'FAIL',
+            'gate: missing bath/tank on wet WO',
+            'blocked' if gate_fired else 'NOT blocked — validation broken')
+    wet_wo.sudo().write({
+        'x_fc_bath_id': saved_bath,
+        'x_fc_tank_id': saved_tank,
+    })
+
 # =====================================================================
 banner('PHASE 5 — Operators run their work orders (REAL-TIME timers)')
 # =====================================================================