从 Twilio 迁移 Verify

I am moving a phone verification integration from Twilio Verify to Bird Verify. 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/verify/migrate/twilio.md for the create, check and status mapping, and https://bird.com/docs/guides/verify/migrate.md for the order the steps go in.
3. Find and list my Twilio Verify usage in this repository before you change anything: the Verifications and VerificationCheck call sites, every Service SID they name and what each Service is configured with, and any place I read a verification status. Bird has no Service segment and no per-request configuration selection, so tell me if I use more than one Service and what differs between them.
4. Tell me early which of these I depend on. Bird Verify has no voice channel and no silent or network-based authentication. It generates the code itself and never returns it, so I cannot supply my own. It accepts `options.language` but no per-request template or message body. Bird can use an existing SMS Sender ID or a connected WhatsApp number with an approved authentication template, configured per channel or country rather than per request; tell me whether my current sender can be kept. Twilio's Service holds code length, TTL, lookup, landline handling and rate limits; on Bird those belong to the workspace rather than to an ID in the path, so tell me which of my Service settings have no home.
5. Configure my channels and destinations following https://bird.com/docs/guides/verify/countries.md and https://bird.com/docs/guides/verify/senders.md. While you are there, disable every country I do not actually verify into. An enabled destination I never send to is not reach, it is exposure to SMS pumping, so ask me which countries I serve rather than leaving the defaults.
6. Port the create and check calls using the mapping tables on the provider page, and move my status handling to Bird's events: https://bird.com/docs/guides/verify/sending-verifications.md and https://bird.com/docs/guides/verify/events.md.
7. Cut over at the create call, not all at once, because a code issued by Twilio Verify cannot be checked by Bird and a code issued by Bird cannot be checked by Twilio Verify. From the moment I say go, send every NEW verification to Bird, and keep routing each check to whichever provider issued that verification. Keep both paths live for one full code lifetime plus margin, then retire the old one. Tell me how you will decide which provider issued a given verification before you write any of it.
8. Test before any real traffic. Bird Verify has no simulated recipients, so do not look for a sandbox: the thing worth testing is the code arriving. Run the integration against a phone number and a mailbox I control, on each channel I enabled, and show me what arrived on each one.
9. Stop and ask me wherever a step needs a decision. Do not start routing new verifications to Bird until I have seen those test results and replied with the words cut over to Bird. Retiring the Twilio Verify path is a separate step: ask me again and wait for me to reply with the words retire the Twilio Verify path, and do not retire it while any code it issued could still be checked. 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.