Feature Request: Separate Domain Verification Resource/Action

Current Behavior

Domain verification currently requires updating the oneuptime_domain resource's is_verified attribute:

1. Create domain with is_verified = false → generates domain_verification_text
2. Create DNS TXT record with verification text
3. Update domain with is_verified = true → triggers verification

This requires a two-step Terraform apply process and feels unnatural in infrastructure-as-code workflows.

Proposed Solution

Add one of the following approaches:

Option 1: Separate verification resource

resource "oneuptime_domain" "example" {
  project_id = "..."
  domain     = "status.example.com"
}

resource "oneuptime_domain_verification" "example" {
  domain_id = oneuptime_domain.example.id
  
  depends_on = [aws_route53_record.verification_txt]
}

Option 2: Verification action via provider function

resource "oneuptime_domain" "example" {
  project_id = "..."
  domain     = "status.example.com"
}

resource "terraform_data" "verify_domain" {
  input = oneuptime_domain.example.domain_verification_text
  
  provisioner "local-exec" {
    command = "oneuptime domain verify ${oneuptime_domain.example.id}"
  }
  
  depends_on = [aws_route53_record.verification_txt]
}

Option 3: Auto-verify on refresh
Make verification happen automatically when the provider detects DNS TXT record exists during refresh, eliminating the need for manual trigger.

Benefits

• More intuitive Terraform workflow
• Single apply after DNS record creation
• Clearer separation of concerns (creation vs verification)
• Better aligns with Terraform best practices

Current Workaround

Users must toggle is_verified from false to true in a second apply after DNS propagation.