Adds a Storms tab driven by three keyless, CORS-enabled feeds:
- api.weather.gov/alerts/active?point=… for watches/warnings/advisories,
with a banner above the content for tornado/severe/Extreme alerts
- SPC Day 1-3 categorical outlooks plus Day 1 tornado/hail/wind
probabilities, resolved by point-in-polygon (nolyr GeoJSON)
- NWS Local Storm Reports via IEM (bounding box + radius cut), nearest first
New: src/lib/api/storm.js (pure helpers + cached fetchers),
src/lib/stores/storm.svelte.js (5-min polling, stale-response guard),
src/components/StormWatch.svelte. Router/nav gain a 'storms' view.
Tests: geometry/parsing (16), store (7), component render (3).
Docs: AGENTS.md storm section + API notes.
