WS-6 binding-target registry references company.kvk_number as a B2B
identity-key candidate. The column needed to exist on the model
before the registry could legitimately reference it. Nullable
because not every Company has a registered KvK (foreign companies,
partners, agencies); identity-key publish guards enforce presence
where required, not at schema level.
Changes:
- New migration `2026_04_28_140000_add_kvk_number_to_companies_table`
adds nullable string column + index after `type`.
- Company::$fillable expanded.
- CompanyFactory generates an 8-digit KvK by default.
- CompanyKvkNumberTest covers attribute persistence, nullability,
and information_schema-verified index existence.
- SCHEMA.md → v2.8 with the new column row + indexes line.
- Schema dump regenerated (CI fast-path).
Migration step counts in 5 backfill tests bumped +1 (the new
migration sits at the top of the migration stack):
- FormFieldBindingMigrationTest: 18→19, 16→17
- ConditionalLogicBackfillTest: 7→8
- FormFieldConfigBackfillAndDropTest: 13→14
- FormFieldOptionsBackfillTest: 3→4
- FormFieldValidationRuleBackfillTest: 16→17
Refs: WS-6 sessie 3a binding-target drift audit
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>