Tax profiles

A TaxProfile carries the slow-moving structural facts about a jurisdiction's consumption tax — never rates or thresholds, which belong in a tax engine's data feeds.

attribute	meaning
`regime`	`vat` · `gst` · `sales_tax` · `none`
`regimeModule`	stable key a tax engine maps to a regime (e.g. `eu-vat`, `us-sales-tax`)
`isEuMember`	member of the EU VAT area — drives reverse-charge / OSS routing
`isSubFederal`	tax is set below the national level — a subdivision is required
`requiresRooftop`	rate resolution needs address-level geocoding

Deny-by-default

A country this package has not modelled resolves to TaxProfile::notModeled() — regime = none, regimeModule = null. Downstream code must treat that as "not taxable here until modelled", never as a silent default rate.

Sub-federal vs rooftop

These are deliberately separate flags:

Canada — isSubFederal = true, requiresRooftop = false. Rates are set at province level; a subdivision fully determines them.
United States — isSubFederal = true, requiresRooftop = true. Rates stack below the state (county, city, special district), so address-level geocoding is needed; a state alone is not enough.
National VAT/GST (EU, UK, CH, NO, AU, NZ, MX) — both false.