Drop company_id column from all 22 domain tables via migration.
Remove companyId from JWT payload, auth plugins, all service method
signatures (~215 occurrences), all route handlers (~105 occurrences),
test runner, test suites, and frontend auth store/types.
The company table stays as store settings (name, timezone). Tenant
isolation in a SaaS deployment would be at the database level (one
DB per customer) not the application level.
All 107 API tests pass. Zero TSC errors across all packages.
Restructure tests into __tests__/ directories at package root so they can
be excluded from production builds. Add unit tests for dates, currency,
lookup service, payment method default logic, and tax exemption state
transitions.
