/*
 * White-label override stylesheet. Empty by default, and **optional**: with no
 * file here the app simply loads no override.
 *
 * Replaceable without a rebuild by mounting the branding folder (the path depends
 * on the setup: `/usr/share/nginx/html/branding` behind the split frontend image,
 * `/app/client/branding` in the single image).
 *
 * Loaded last in index.html, so it can override any style.
 */