- Add TestMain to set test env vars and testdb.TruncateTables for test
isolation
- Add chi routing context to test helpers for path parameter extraction
- Fix SQL error handling to use errors.Is() instead of ==
- Add validators package with ID validation
- Fix admin test middleware chain (RequireAdmin wrapper)
- Update test user inserts to include phone and date_of_birth fields
- Update service delete test to check soft-delete (is_active=false)
- Update holiday hours test to use new schema (weekday, is_open)
- Add phone number validation tests for UK mobile numbers