Create a customer in the authenticated shop scope.

Authentication: API key required

Behavior

• At least one of email or phone_number is required.
• The shop is not provided in the request body. It is derived from the API key.
• If the shop does not exist, the route returns 404 Shop not found.
• If a customer already exists with the same email, the route returns HTTP 200 with success: true and existing: true instead of creating a duplicate.
• If a customer already exists with the same phone_number, the route also returns the existing customer with HTTP 200.
• shopify_id, wordpress_id, fb_user_id, ig_user_id, and whatsapp_id are converted to strings before persistence when present.

{
  "email": "dev@example.com",
  "first_name": "Ada",
  "last_name": "Lovelace",
  "phone_number": "+33123456789",
  "shopify_id": 987654321
}

{
  "success": true,
  "customer": {
    "id": 123,
    "email": "dev@example.com",
    "phone_number": "+33123456789",
    "first_name": "Ada",
    "last_name": "Lovelace",
    "shopify_id": "987654321",
    "shopDomain": "example.myshopify.com"
  }
}