It turns out that { elements: { type: 'string' } }
is correct per the docs: https://ajv.js.org/json-type-definition.html#elements-form
but an auto-import occurred that resulted in the wrong import path being used.
Incorrect import caused the issue: import Ajv from 'ajv';
Corrected import resolved the issue: import Ajv from 'ajv/dist/jtd';