Clone unified test set
Full-clone a unified test set. Returns a job id (async).
Body: * new_test_set_name (str, required) — must be unique per (company_id, application_id). * new_test_set_description (str, optional) — defaults to source’s description.
Response: 202 Accepted with {job_id, status: "pending"}. The portal subscribes to the TEST_SET_JOB_PROGRESS websocket keyed on job_id and polls GET /api/v1/test-set-jobs/{job_id} as fallback. On completion the job’s result is the newly-cloned TestSet payload — same shape GET /api/v1/unified-test-sets/{id} returns.
Because the unified surface stores item payload inline, the clone is one SQL round-trip per phase (set + items+response_subs). Sample cloning isn’t offered for the unified family yet — add a sample_mode branch here when it lands.