Add prospects bulk

Add multiple prospects to a campaign at once. Maximum 1000 per request. Each prospect must include a valid linkedinUrl (https://linkedin.com/in/<slug>); firstName/lastName/email/company/position are optional. Custom fields beyond those are stored as customFields. For imports >1000, chunk client-side: omit prospectListId on the first call to create a list (response returns prospectListId), then pass that same prospectListId on subsequent calls so all chunks land in the same list. The Pipeline CLI exposes a sugar wrapper `pipeline import-prospects --file leads.csv --campaign-id X` that handles the chunking automatically. Returns { added, failed, errors, prospectListId }.

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "add-prospects-bulk",
    "arguments": {
      "campaignId": "00000000-0000-4000-8000-000000000000",
      "prospects": [
        {}
      ]
    }
  }
}