api-server is internal-only after C5 (no host port in prod compose),
so the permissive 'CORS(app)' default never fires in normal operation.
Removing it eliminates a stale '*' Access-Control-Allow-Origin that
would become attack surface if a host port were ever accidentally
re-exposed.
Server-side fetches from web-view (legacy Flask) and web-next
(Next.js RSC) don't trigger CORS — that's a browser-only mechanism.
flask_cors stays in requirements.txt because cm_web_view.py still
imports it; both get removed in B4 when the legacy web-view retires.