feat: v0.6.0 — data foundation: Drizzle ORM + SQLite (sql.js/WASM) persistence, first-run seed, read-only GET /api/state snapshot

2026-09-17 11:51:42 +00:00
parent 4d9a1e9fa9
commit 7fdc43bc7e
23 changed files with 1006 additions and 8 deletions
@@ -0,0 +1,12 @@
+const EARTH_RADIUS_KM = 6371;
+
+// Great-circle distance between two WGS84 points (haversine), in km.
+export function haversineKm(lat1: number, lon1: number, lat2: number, lon2: number): number {
+  const toRad = (d: number) => (d * Math.PI) / 180;
+  const dLat = toRad(lat2 - lat1);
+  const dLon = toRad(lon2 - lon1);
+  const a =
+    Math.sin(dLat / 2) ** 2 +
+    Math.cos(toRad(lat1)) * Math.cos(toRad(lat2)) * Math.sin(dLon / 2) ** 2;
+  return 2 * EARTH_RADIUS_KM * Math.asin(Math.min(1, Math.sqrt(a)));
+}