feat(reports): split customer-facing line header into Part Number + Description columns

User request: on customer-facing PDFs the single "Part" column was
stacking part number + revision + description together. Split into
two distinct columns so customers see Part Number in its own field
and the Description column carries only the prose.

Macro split:
  * customer_line_part_number — strong part number + "(Rev X)"
  * customer_line_description  — line.name + any populated line
    metadata (serial, job#, thickness)
  * customer_line_header (legacy) kept as a thin wrapper that
    t-calls both macros stacked so older reports still render.

Reports updated — each gains a new first "PART NUMBER" column and
the old "PART" column renamed to "DESCRIPTION":
  * report_fp_sale (both portrait variants)
  * report_fp_invoice (both portrait variants)
  * report_fp_packing_slip (both variants — delivery + MO-origin)

Column widths rebalanced per report. Section / note colspans bumped
to account for the extra column.

report_fp_bol left as-is — its "Description of Goods" td is a
freight-convention combined field, intentionally keeps the stacked
layout via the legacy customer_line_header macro.

fusion_plating_reports → 19.0.6.0.0

Co-Authored-By: Claude Opus 4.7 (1M context) <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': '19.0.5.1.0',
+    'version': '19.0.6.0.0',
     'category': 'Manufacturing/Plating',
     'summary': 'PDF reports for Fusion Plating: quote, SO, WO, packing, BoL, CoC, invoice, receipt, quality + compliance.',
     'depends': [