A "cut to radar" PiP recipe: a Leaflet map (vendored locally for the
CSP) with a CARTO dark basemap, an animated RainViewer radar loop, and
live NWS warning polygons drawn and color-coded (tornado/severe-tstorm/
flash-flood/flood) with a pulsing "LIVE RADAR" HUD, count chips, and a
legend. Auto-frames the view to the active warning polygon(s).
Two modes: "always" (radar always up) and "on_warning" (default) which
shows the radar only while a qualifying warning covers the configured
point and clears it when the warnings expire — like a station breaking
in during severe weather.
100% keyless / open data: RainViewer radar, CARTO/OSM basemap, NWS
alerts. Zero Node deps; Leaflet is vendored client-side via
vendor-leaflet.sh (gitignored). Offline test covers the warning gate,
color map, RainViewer tile-URL builder, and overlay-URI round-trip.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
