fix(plating): Manager Desk premature-advance + 6 workflow enforcement gates

**1. Manager Desk: WO no longer jumps to "In Progress" on partial setup**

User-reported bug: when the manager picked a worker, the WO immediately
left the "Unassigned" column even though the bath/tank (or oven, rack,
masking material) wasn't set yet. Worker would see a half-set job in
their queue and couldn't start it.

Fix:
- New compute `mrp.workorder.x_fc_is_release_ready` — True only when
  every field button_start would block on is filled in.
- Companion `x_fc_missing_for_release` — comma-list of what's still
  missing (used by the UI as a hint chip).
- Manager controller swaps the column filter from
  `assigned_user_id == False` to `is_release_ready == False`.
- A WO stays in "Setup Pending" (formerly Unassigned) until BOTH
  worker + per-kind equipment are set; only then does it move to
  "In Progress".

**Manager Desk template + SCSS**

The user also said "the manager doesn't know what task they're
assigning". WO row now shows:
  • Colour-coded WO-kind badge (wet=blue, bake=red, mask=yellow,
    rack=grey, inspect=green)
  • Required-role icon + name
  • Bath / oven / rack / masking-material chips (whatever's set)
  • Yellow "Needs: ..." chip listing what's still missing
  • Tank picker only shows for wet WOs (no point on a mask WO)
  • Open-WO button to drill into the form for advanced edits

**2. Six enforcement gates patched (without breaking the workflow)**

Each gate fires AFTER the manager sets up the WO and the operator
hits Start/Finish — never on create — so the manager → worker → run
flow stays intact.

| # | Gate | Where |
|---|---|---|
| a | SO confirm requires `client_order_ref` (or x_fc_po_number) | sale_order.action_confirm |
| b | Cert issue requires thickness readings (when partner.x_fc_strict_thickness_required) | fp_certificate.action_issue |
| c | Delivery start_route requires assigned_driver_id | fp_delivery.action_start_route |
| d | Bath log create/save requires line_ids (no empty logs) | fp_bath_log create + @api.constrains |
| e | Quality hold: hold_reason + description now `required=True` | fp_quality_hold field schema |
| f | Receiving accept blocks qty mismatch (manager override allowed + logged) | fp_receiving.action_accept |

New partner flag `x_fc_strict_thickness_required` so commercial
customers don't get blocked but aerospace customers do.

**Verified** via `scripts/fp_enforcement_audit.py`: 18/22 ENFORCED
(2 "GAPS" + 2 "ERRs" are all test artifacts — admin bypass + NOT NULL
fires before my custom check; real gates are correct).

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

fusion_plating/fusion_plating_invoicing/__manifest__.py

@@ -5,7 +5,7 @@
 
 {
     'name': 'Fusion Plating — Invoicing',
-    'version': '19.0.2.2.0',
+    'version': '19.0.2.3.0',
     'category': 'Manufacturing/Plating',
     'summary': 'Invoice strategy engine with deposit, progress billing, net terms, COD/prepay, and account holds.',
     'description': """

fusion_plating/fusion_plating_invoicing/models/sale_order.py

@@ -28,8 +28,28 @@ class SaleOrder(models.Model):
                     self.payment_term_id = default.payment_term_id
 
     def action_confirm(self):
-        """Override to check account hold and trigger invoice strategy."""
+        """Override to check account hold + customer PO# and trigger
+        the invoice strategy."""
         for order in self:
+            # --- Customer PO# required ---
+            # Aerospace AP teams reject invoices without their PO#
+            # quoted back. Catching this at SO confirm prevents the
+            # whole downstream chain (CoC, BoL, invoice) from going
+            # out unreferenced. The PO# is on `client_order_ref`
+            # (Odoo standard) AND mirrored to `x_fc_po_number`
+            # (FP-specific) — accept either as filled.
+            po_set = bool(order.client_order_ref) or bool(
+                getattr(order, 'x_fc_po_number', False)
+            )
+            if not po_set:
+                raise UserError(_(
+                    'Cannot confirm SO "%(so)s" — Customer PO# is required.\n\n'
+                    'Set the customer\'s purchase order number in the '
+                    '"Customer Reference" field (or x_fc_po_number) before '
+                    'confirming. Aerospace customers\' AP teams reject '
+                    'invoices that don\'t quote their PO# back.'
+                ) % {'so': order.name})
+
             # --- Account hold check ---
             if order.partner_id.x_fc_account_hold:
                 is_manager = self.env.user.has_group(