get_campaign_readiness

Check what launching a review-invite campaign would run into, WITHOUT launching it: `canLaunch`, every unmet prerequisite in `blockers` (code + explanation — a verified sending domain for EMAIL, a carrier-approved number for SMS, a valid campaignType), `warnings` (no recipients, none with an email, none with SMS consent) and recipient coverage counts. Run this before run_campaign_action publish; it uses the same checks the launch does.

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "get_campaign_readiness",
    "arguments": {
      "campaignId": "string"
    }
  }
}

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "content": [
      {
        "type": "text",
        "text": "..."
      }
    ]
  }
}