feat(fusion_accounting_reports): seed balance sheet report definition

Adds data/report_balance_sheet.xml with sections for assets, liabilities,
and equity, using the V19 account_type prefixes (asset_current,
asset_receivable, asset_cash, asset_prepayments, asset_non_current,
asset_fixed; liability_payable, liability_credit_card, liability_current,
liability_non_current; equity). Header rows ('ASSETS', 'LIABILITIES',
'EQUITY') are present for visual structure -- the line resolver currently
skips spec entries without compute or account_type_prefix, which means
they don't render but also don't disturb subtotal counts.

Bumps manifest to 19.0.1.0.6.

Made-with: Cursor

fusion_accounting_reports/__manifest__.py

@@ -1,6 +1,6 @@
 {
     'name': 'Fusion Accounting Reports',
-    'version': '19.0.1.0.5',
+    'version': '19.0.1.0.6',
     'category': 'Accounting/Accounting',
     'summary': 'AI-augmented financial reports (P&L, balance sheet, trial balance, GL).',
     'description': """
@@ -32,6 +32,7 @@ menu hides; the engine and AI tools remain available for the chat.
     'data': [
         'security/ir.model.access.csv',
         'data/report_pnl.xml',
+        'data/report_balance_sheet.xml',
     ],
     'assets': {
         'web.assets_backend': [