patch
https://api.preczn.com/v1/forms//locations/
Form-scoped equivalent of PATCH /v1/merchants/:merchantId/locations/:locationId. Provided fields replace, omitted fields are untouched. name, address, mcc and phone may not be set to null. bankingId is the one nullable field — a valid account id assigns (re-validated against the merchant's banking[]), null clears. primaryLocationId is NOT settable here; use PUT /v1/forms/:formId/primary-location. Any unrecognized field returns 400 rather than being silently ignored.
400Validation failure, an unrecognized field, a null core field, a bankingId that does not match a bank account on this merchant, or the form has expired ({ expirationUrl }).
404Form, merchant, or location not found.
