List session files

curl --request GET \
  --url https://api.case.dev/agent/v1/chat/{id}/files \
  --header 'Authorization: Bearer <token>'

{
  "chatId": "<string>",
  "files": [
    {
      "path": "<string>",
      "name": "<string>",
      "sizeBytes": 123
    }
  ]
}