Send a template message to many recipients

Send a specific template message to many recipients at once. Don't worry about the structure of each recipient, if the data is in the body AI will take care of it. Every bulk send is grouped under a campaign. Pass a "campaign" object to group this call with other sends under your own campaign identifier (same id → same campaign, created on first use). When the object is present, "id" and "name" are required; "intent" is optional — ideally one of the known values, but any custom string is accepted, and if omitted Vambe infers it from the template with AI. If the whole object is omitted, a campaign named after the template and date is created automatically for this call.