Start owner OIDC flow

Initiates the OIDC authorization code flow to create the instance owner. Returns an authorization URL for the frontend to redirect to.

curl -X POST "https://example.com/v1/setup/owner/start-oidc" \  -H "Content-Type: application/json" \  -d '{    "redirect_uri": "string"  }'

{  "authorization_url": "string",  "state": "string"}