Metadata correction for R19-1036

### JSON data block

```json
{
"anthology_id": "R19-1036",
"authors": [
{
"first": "Diego de Vargas",
"last": "Feijo",
"id": "diego-feijo/unverified"
},
{
"first": "Viviane Pereira",
"last": "Moreira",
"id": "viviane-moreira"
}
],
"authors_old": "Diego Feijo | Viviane Moreira",
"authors_new": "Diego de Vargas Feijo | Viviane Pereira Moreira"
}
```

Use the JSON body as the exact request: anthology_id R19-1036 should swap `authors_old` to `authors_new`. First locate the stored metadata entry for this anthology ID by searching the repo for `R19-1036` or `Diego Feijo`, then update only the author name fields to match the provided replacement. No files, tests, or commands are named, so done means the R19-1036 record now displays the corrected author spellings.

Written by the indexing model from the issue text.