SPF / DKIM / DMARC for neurontechnologies.ai are managed via the Cloudflare
API rather than Terraform because the cloudflare_record provider rewrites
name="@" on apply, which forces replacement of the apex SPF record and
opens a propagation gap. A duplicate (malformed-quoted) apex SPF that was
causing Gmail to fail SPF was also removed via the API; the surviving
record is the canonical one and is documented here for traceability.