Start a brand-guideline (PDF) extraction

Uploads a brand-guideline PDF and queues an AI extraction into the canonical brand schema. Poll GET /brand_guideline_extractions/{id} until `status` is `review`, inspect the `draft`, then POST .../commit to apply it. Requires the OpenAI integration to be configured.

curl -X POST "https://example.com/brand_guideline_extractions" \  -H "Content-Type: application/json" \  -d '{    "content_base64": "string"  }'

{  "id": "string",  "object": "brand_guideline_extraction",  "status": "queued"}

{  "error": {}}

{  "error": {}}

{  "error": {}}