Diagnose sending and receiving problems in the workspace

Read-only troubleshooting snapshot from stored state: an issues list in plain language, plan and usage against limits, each domain's DKIM and inbound state, sending identities, 30-day deliverability and sender reputation, suppressions and unsubscribes, the last 30 days of messages that were not sent with their reasons, bounce, complaint and reject events, and webhook delivery health. Never returns message bodies, API keys or webhook secrets.