从 Brevo 迁移

I am moving an email integration from Brevo to Bird. Route through it with me.
1. Check what you already have before setting anything up. If Bird's MCP server is connected, use its tools. If the Bird CLI is installed and signed in, use that. Either one is enough, and every step below is an action you take with whichever you have. Only if neither is present, follow https://bird.com/docs/ai/set-up-your-agent.md to set one up and sign me in. Every Bird docs page serves Markdown at its own URL with `.md` appended, so fetch that rather than the HTML.
2. Read https://bird.com/docs/guides/email/migrate/brevo.md for the payload, suppression and webhook mapping, and https://bird.com/docs/guides/email/migrate.md for the order the steps go in.
3. Find and list my Brevo usage in this repository before you change anything: calls to /v3/smtp/email and any SDK wrappers around them, whether I send with templateId or with htmlContent, the webhook handler and the URL it is registered at, and every domain I send from. Tell me the list before you edit anything.
4. Register each of those sending domains with Bird and give me the DNS records to publish, following https://bird.com/docs/guides/email/sending-domains.md. Leave every DNS record Brevo uses exactly as it is: Bird's records are published alongside them and both providers authenticate side by side until I switch traffic. Publishing DNS affects mail for the whole domain, so show me the records and let me publish them.
5. Export my suppressions and import them into Bird before any production traffic goes through Bird, so my first sends do not reach addresses that already bounced or complained. Brevo holds these in two separate places and I need both: GET /v3/smtp/blockedContacts for transactional blocks and unsubscribes, and the marketing blocklist, which lives on the contact records as emailBlacklisted rather than on a suppression endpoint. Page through both. The Bird import takes one address per request and is idempotent, so a partial re-run is safe. https://bird.com/docs/guides/email/suppressions.md has the reason taxonomy.
6. Port the send call and the webhook handler using the mapping tables on the provider page. Brevo's webhook security page documents credentials I configure on the endpoint rather than a payload signature, so check what my endpoint actually relies on today: if it is a username and password in the webhook URL, take them out and tell me to rotate that pair rather than reusing it, because a credential that has lived in a URL should be treated as exposed. Bird signs every delivery instead. https://bird.com/docs/guides/webhooks.md and https://bird.com/docs/guides/email/events.md.
7. Run my whole integration against Bird's mail sandbox before any production traffic, following https://bird.com/docs/guides/email/testing-sandbox.md. Sandbox sends run the real pipeline without reaching an inbox or touching my sending reputation.
8. Stop and ask me wherever a step needs a decision. Do not point production traffic at Bird until I have seen the sandbox results and replied with the words cut over to Bird. Retiring the Brevo path is a separate step that comes later: ask me again and wait for me to reply with the words retire the Brevo path. A reply that agrees without naming what it is authorising is not authorisation. Finish by telling me what is left that only a person can do.