feat(numbering): wire CoC/RCV/DLV/PU into parent-numbered mixin + rename counters

Per-model counter fields on sale.order renamed to x_fc_pn_*_count
to avoid collision with pre-existing compute fields of the same
short name in bridge_mrp / receiving / configurator (silent
compute-override was suppressing the storage). 4 child models
(fp.certificate, fp.receiving, fusion.plating.delivery,
fusion.plating.pickup.request) now derive names as PFX-<parent>
with -NN suffix from the 2nd onward.

fusion.plating.pickup.request gains a sale_order_id field
(optional) so pickups created against an SO get parent-derived
names, while standalone pickups (pre-SO) fall back to PU/YYYY/NNNN.

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

fusion_plating/fusion_plating_certificates/models/fp_certificate.py

@@ -20,7 +20,7 @@ class FpCertificate(models.Model):
     """
     _name = 'fp.certificate'
     _description = 'Fusion Plating — Certificate'
-    _inherit = ['mail.thread', 'mail.activity.mixin']
+    _inherit = ['mail.thread', 'mail.activity.mixin', 'fp.parent.numbered.mixin']
     _order = 'issue_date desc, id desc'
 
     name = fields.Char(string='Reference', readonly=True, copy=False, default='New')
@@ -271,14 +271,22 @@ class FpCertificate(models.Model):
             rec.trend_alert = alert
             rec.trend_explanation = explanation
 
-    # ----- Sequence + spec-limit auto-fill ---------------------------------
+    # ----- Parent-numbered mixin hooks -------------------------------------
+    def _fp_parent_sale_order(self):
+        return self.sale_order_id
+
+    def _fp_name_prefix(self):
+        return 'CoC'
+
+    def _fp_parent_counter_field(self):
+        return 'x_fc_pn_cert_count'
+
+    # ----- Create: parent-derived name (fallback to legacy sequence) -------
     @api.model_create_multi
     def create(self, vals_list):
         SaleOrder = self.env['sale.order']
         for vals in vals_list:
-            if vals.get('name', 'New') == 'New':
-                vals['name'] = self.env['ir.sequence'].next_by_code('fp.certificate') or 'New'
-            # Pull thickness spec limits from coating config if not set
+            # Spec-limit auto-fill (existing behaviour, preserved).
             already_set = vals.get('spec_min_mils') or vals.get('spec_max_mils')
             if not already_set and vals.get('sale_order_id'):
                 so = SaleOrder.browse(vals['sale_order_id'])
@@ -286,7 +294,23 @@ class FpCertificate(models.Model):
                 if cfg and cfg.thickness_uom == 'mils':
                     vals.setdefault('spec_min_mils', cfg.thickness_min or 0.0)
                     vals.setdefault('spec_max_mils', cfg.thickness_max or 0.0)
-        return super().create(vals_list)
+            # Defer naming: let the record exist so the mixin can write
+            # name via raw SQL, then fall back to the legacy sequence if
+            # no parent SO is reachable.
+            if not vals.get('name'):
+                vals['name'] = 'New'
+        records = super().create(vals_list)
+        for rec in records:
+            if rec.name and rec.name != 'New':
+                continue
+            if not rec._fp_assign_parent_name():
+                seq = self.env['ir.sequence'].next_by_code('fp.certificate') or 'New'
+                self.env.cr.execute(
+                    "UPDATE fp_certificate SET name = %s WHERE id = %s",
+                    (seq, rec.id),
+                )
+                rec.invalidate_recordset(['name'])
+        return records
 
     # ----- State actions ----------------------------------------------------
     def action_issue(self):