feat(plating): CoC spec-optional + SO-style header + thickness for any cert

- Drop the hard spec_reference gate on fp.certificate.action_issue. The
  customer-facing description (_fp_resolve_customer_facing_description,
  walks job -> SO line, reuses fp_customer_description) now drives the CoC
  Process column; spec_reference prints only when an estimator fills it.
- CoC EN/FR reports swap web.external_layout for fp_external_layout_clean +
  paperformat_fp_a4_portrait. New shared coc_header (company logo + address
  left, Nadcap logo centre, title + Code128 barcode right) mirrors the Sale
  Order header. Removed the 3-logo Nadcap/AS9100/CGP accreditation strip and
  the body H1s; padding-top 0 on both body wrappers.
- Un-gate the Issue Certs wizard thickness upload (was invisible unless the
  customer was thickness-flagged) so a Fischerscope report can be attached to
  ANY cert; merge (page 2) + inline readings already render unconditionally.
- Update issue-gate tests, bump versions (certificates 19.0.9.1.0,
  reports 19.0.11.27.0, jobs 19.0.11.2.0), record CLAUDE.md rule 14c.

Deployed + render-verified on entech (CoC-30065, 223KB PDF, no QWeb errors).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

fusion_plating/fusion_plating_reports/__manifest__.py

@@ -3,7 +3,7 @@
 # License OPL-1 (Odoo Proprietary License v1.0)
 {
     'name': 'Fusion Plating — Reports',
-    'version': '19.0.11.26.31',
+    'version': '19.0.11.27.0',
     'category': 'Manufacturing/Plating',
     'summary': 'PDF reports for Fusion Plating: quote, SO, WO, packing, BoL, CoC, invoice, receipt, quality + compliance.',
     'depends': [