Drop plugin card icons (PNG) in this folder and reference it from plugin.json
via "icons_dir": "icons". If your plugin also sets plugin_icons_dir on the
class (see mixlar.plugin), the app copies those PNGs into its flat icons/
folder with a short prefix derived from your plugin id at load time.

This starter ships no icons — plugin_icon in plugin.json ("fa5s.star") is a
Font Awesome name and needs nothing here. This folder just needs to exist so
'mixlar-sdk validate' doesn't warn about a missing icons_dir.
