Maps · World: choropleths and the world's countries

ChoroplethLayer washes each area by its value, keyed by its id or a
property's text or number, on one hue's scale from its faintest at the
least value to its strongest at the most; an area without a value reads
as no data. ChoroplethMap lays it on the owner's map, with or without
tiles, and puts a legend of the scale and of no data in the corner; a
value that matches no area is logged once. WorldMap washes Natural
Earth's 110m countries, bundled trimmed by scripts/countries.py, by ISO
3166 alpha-2 code, and fails on a key that is no code. A shape now
paints as one fill and one edge path per world in view.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/maps/view.rs

@@ -46,7 +46,7 @@ pub struct MapView {
     pub(crate) viewport: MapViewport,
     tiles: Option<TileSource>,
     zooms: (u8, u8),
-    attribution: Option<SharedString>,
+    pub(crate) attribution: Option<SharedString>,
     layers: Vec<MapLayer>,
     markers: Vec<MapMarker>,
     gathered: bool,