Serves the typed icon set as SVG, so an entity's icon_url can point at an icon we already ship instead of an image someone has to host.

GET /icons/trophy.svg

The web UI does not actually fetch these — it recognises its own URLs and inlines the SVG so currentColor follows the theme. This route is for everyone else: game clients, mobile, anything reading icon_url from the API.

The body is a compile-time constant keyed by name, so it can be cached forever.