fix(certificates): honour recipe thickness suppression at cert issue

The recipe-cert-toggles feature (fb6cccc8) taught
fp.job._resolve_required_cert_types to suppress thickness for recipes
with requires_thickness_report=False (passivation, chemical conversion,
anodize seal-only). But the actual thickness-data ENFORCEMENT never got
the memo: both fp.certificate.action_issue's hard gate AND the
Issue-Certs wizard's readiness hint re-derived 'needs thickness' from
partner flags only and ignored the recipe. Result: a passivation CoC for
a thickness/strict customer could never be issued — the gate demanded
Fischerscope data the process physically cannot produce.

Consolidate the partner-flag + recipe-suppression logic into one
fp.certificate._fp_needs_thickness_data() helper and route both the gate
and the wizard through it, so the cert-type resolver and the issue-time
gate can never drift again. Add regression tests: passivation recipe
suppresses the issue gate even for strict-thickness customers; a normal
recipe still enforces (control, guards aerospace).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

fusion_plating/fusion_plating_certificates/__manifest__.py

@@ -5,7 +5,7 @@
 
 {
     'name': 'Fusion Plating — Certificates',
-    'version': '19.0.9.3.0',
+    'version': '19.0.9.4.0',
     'category': 'Manufacturing/Plating',
     'summary': 'Certificate registry for CoC, thickness reports, and quality documents.',
     'description': """