curl --request GET \
  --url https://geoff.ai/api/v1/files \
  --header 'Authorization: Bearer <token>'

{
  "data": [
    {
      "file_id": "file_abc123",
      "filename": "image.jpg",
      "size": 1048576,
      "purpose": "image-input",
      "created_at": "2026-01-01T00:00:00Z"
    }
  ]
}