List brands

curl https://api.paintvisualizer.ai/v1/brands \
  -H "Authorization: Bearer pv_your_key"

{
  "data": [
    { "slug": "sherwin-williams", "name": "Sherwin-Williams" },
    { "slug": "benjamin-moore", "name": "Benjamin Moore" },
    { "slug": "behr", "name": "Behr" },
    { "slug": "farrow-and-ball", "name": "Farrow & Ball" },
    { "slug": "ppg", "name": "PPG" },
    { "slug": "valspar", "name": "Valspar" },
    { "slug": "dunn-edwards", "name": "Dunn-Edwards" },
    { "slug": "glidden", "name": "Glidden" }
  ]
}