Configure app-managed custom fields on Jobber clients, quotes, jobs, and invoices via GraphQL

Steps

1. Confirm your app has been granted the Custom Field Configurations scope with write access
2. Before creating a new custom field, query customFieldConfigurations to check whether a field with the same purpose already exists on the account (important after disconnect/reconnect cycles)
3. Create a configuration with the appropriate mutation for the value type you need (Text, Numeric, Area, Dropdown, TrueFalse, or the app-only Link type via customFieldConfigurationCreateLink), specifying appliesTo, name, transferable, readOnly, and defaultValue
4. Set values on individual objects by including a customFields array (referencing the configuration ID) in the relevant create/edit mutation, e.g. clientCreate or clientEdit
5. When editing an existing custom field value, query the object first to get the field value's own ID, since edit mutations reference the value ID, not the configuration ID
6. Handle the archived-on-disconnect lifecycle: your app's custom fields are archived automatically when a user disconnects, and unarchived automatically on reconnect