Set up a verified publisher on pub.dev

[Amayyas]

Why

The package currently shows as "Unverified uploader" on pub.dev. A verified publisher (tied to a domain) looks more trustworthy and is the norm for established packages.

How

Requires owning a domain (e.g. amayyas.dev). Once available:

1. Go to the package's pub.dev admin page.
2. Follow the "Verified Publisher" flow (domain ownership verification via DNS TXT record or similar — check current pub.dev docs at implementation time, the process may have changed).
3. Transfer/associate flutter_ai_sdk to the verified publisher.

Definition of done

• Domain acquired
• Verified publisher created and package associated with it
• pub.dev page shows the verified publisher badge instead of "Unverified uploader"