XML defines 8 positions with auto-detection by country/state:
- CA Ontario (default), CA Atlantic, CA Quebec, CA BC, CA Prairies/Territories
- Export US, Export International, Tax Exempt
post_init hook _configure_fiscal_position_tax_maps sets up bidirectional
tax routing (sale + purchase) from the default '5% GST' to the appropriate
provincial tax via Odoo 19's account.fiscal.position.tax_ids /
account.tax.original_tax_ids relation.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
