fix(fusion_plating_jobs): vertically center the full-width QR (no-tags external)

The no-tags QR used line-height centering, which wkhtmltopdf renders slightly
high (extra white at the bottom). Switched to a single-cell table with
vertical-align:middle (same mechanism as the with-tags case) so the QR centers
in its cell with balanced top/bottom margin. Verified live (WO-30072).

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

fusion_plating/fusion_plating_jobs/__manifest__.py

@@ -3,7 +3,7 @@
 # License OPL-1 (Odoo Proprietary License v1.0)
 {
     'name': 'Fusion Plating — Native Jobs',
-    'version': '19.0.12.1.4',
+    'version': '19.0.12.1.5',
     'category': 'Manufacturing/Plating',
     'summary': 'Native plating job model — replaces mrp.production / mrp.workorder bridge.',
     'author': 'Nexa Systems Inc.',