Drop your icon PNGs in this folder, named exactly like this (lowercase, matches the
WeatherIcon enum constant names in com.weatherforecast.data.WeatherIcon):

clear_sky.png
mainly_clear.png
partly_cloudy.png
overcast.png
fog.png
depositing_rime_fog.png
light_drizzle.png
moderate_drizzle.png
dense_drizzle.png
light_freezing_drizzle.png
dense_freezing_drizzle.png
slight_rain.png
moderate_rain.png
heavy_rain.png
light_freezing_rain.png
heavy_freezing_rain.png
slight_snow_fall.png
moderate_snow_fall.png
heavy_snow_fall.png
snow_grains.png
slight_rain_showers.png
moderate_rain_showers.png
violent_rain_showers.png
slight_snow_showers.png
heavy_snow_showers.png
thunderstorm.png
thunderstorm_slight_hail.png
thunderstorm_heavy_hail.png

(unknown.png is optional - it's only used if Open-Meteo ever returns a code outside its
own official table, which shouldn't normally happen.)

Any PNG you add here is picked up automatically, with no code changes and no rebuild of
game logic needed - just a resource reload (F3+T in-game, or a restart). Icons you
haven't added yet keep showing their English text name instead, so you can do this one
icon at a time.

Recommended: square PNGs, transparent background, at least 32x32px (they're drawn 1:1,
not scaled, so bigger source images just get cropped to the top-left corner - keep them
square and match the sizes used in IconRenderer's draw() calls: 16px in the HUD, 32px in
the forecast menu, unless you change those numbers too).
