feat(invoicing): managers (+QM+Owner) can create customer invoices

Grant Odoo Billing (account.group_account_invoice) to group_fp_manager via
implied_ids; Quality Manager + Owner inherit it. Billing only (not Accountant);
the SO-origin workflow gate in fusion_plating_jobs is unchanged, so managers
invoice from the Sale Order's Create Invoice action. Tests assert Manager/Owner
get Billing and Shop Manager does not.

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

fusion_plating/fusion_plating_invoicing/__manifest__.py

@@ -5,7 +5,7 @@
 
 {
     'name': 'Fusion Plating — Invoicing',
-    'version': '19.0.3.7.0',
+    'version': '19.0.3.8.0',
     'category': 'Manufacturing/Plating',
     'summary': 'Invoice strategy engine with deposit, progress billing, net terms, COD/prepay, and account holds.',
     'description': """