Log activities and move candidates through pipeline stages via the Crelate API

Steps

1. Authenticate with the api_key querystring parameter against base https://app.crelate.com/api3/.
2. To log an interaction, create a Note or Task activity; both entity types require a Body field — omitting it returns HTTP 500 with the missing-field list.
3. Tag activities (or other taggable records) by including a Tags object keyed by your organization's tag category names — use 'Default' for your default category, e.g. Tags: { Default: [...], Skills: [...] } for a custom 'Skills' category.
4. To move a candidate into a job's recruiting pipeline, use the 'Add Contact To Job' (single contact) or 'Add Contacts To Job' (multiple contacts) endpoint, which adds the contact(s) to the specified job's pipeline at a given workflow stage.
5. To discover valid stage/status values first, call the GetWorkflowStatuses endpoint, which supports filtering to a single workflow status type per call.
6. Confirm exact request/response shapes for Add Contact To Job and GetWorkflowStatuses against the live interactive reference at https://app.crelate.com/api3/docs before building against them.