Kicks off a paginated import from a LinkedIn / Sales Navigator search against the connected `accountId`. Returns immediately — the worker picks the job up on its next cron tick (within 1 minute). Provide **either**: - `url`: a copied LinkedIn search URL (classic or Sales Navigator), or - `params`: a structured filter blob (`{ api, category, keywords, ... }`). Imported leads land in `listId` if provided; otherwise a new list is auto-created and returned in the response.