Icon Atlas
Wind barb sprite atlas (parity with JS icon.atlas: ordered ids and speed step in m/s per index).
The default ids are mapsgl:wind-barb-0 … mapsgl:wind-barb-100 in 5 kt steps. intervalMs is the bucket width in m/s (JS: 5 * 0.5144444). Instanced GL barbs still draw procedurally in com.xweather.mapsgl.renderers.WindBarbInstancedRenderer; keep IconPaint.image consistent with these ids for any Mapbox symbol / tooling path.