Integrate AutoSend with v0

Integrate AutoSend email API for sending transactional emails.

API Details:
- Base URL: https://api.autosend.com/v1
- Auth: Bearer token using API key stored in environment variable AUTOSEND_API_KEY
- Endpoint: POST /mails/send
- Content-Type: application/json

Request body format:
{
  "to": { "email": "[email protected]", "name": "Jane Doe" },
  "from": { "email": "[email protected]", "name": "Your App Name" },
  "subject": "Your subject line",
  "html": "<h1>Hello!</h1><p>Your email content here.</p>"
}

Response format:
{
  "success": true,
  "data": {
    "emailId": "698afb75ff4bc5466e3a797a",
    "message": "Email queued successfully.",
    "totalRecipients": 1
  }
}

Create a Next.js API route (app/api/send-email/route.ts) that:
1. Reads AUTOSEND_API_KEY from process.env
2. Accepts to, from, subject, and html in the request body
3. Calls the AutoSend API with Bearer token auth
4. Returns the response to the client

The "from" email must use a domain verified in AutoSend.

Docs: https://docs.autosend.com/quickstart/email-using-api