Show leg distance in km on job list and on-board contracts (ISS-095, v0.48.0)

lib/game/state.ts

@@ -62,6 +62,8 @@ export interface PackageState {
   weightKg: number;
   // Special status (v0.37.0, ISS-073) — key into lib/game/specials.ts SPECIALS; null = none.
   special: string | null;
+  // Great-circle leg distance in km (v0.48.0, ISS-095) — computed from airport coords, not stored.
+  distanceKm: number;
   deadlineSimTime: number;
   // 'ignored' (v0.29.0, ISS-047 part B) = a dismissed open job — terminal, leaves the market.
   status: 'open' | 'loaded' | 'delivered' | 'expired' | 'abandoned' | 'ignored';
@@ -100,6 +102,12 @@ export async function getStateSnapshot(): Promise<StateSnapshot> {
   const nameByIcao = new Map(fc.features.map((f) => [f.properties.icao, f.properties.name]));
   const nameOf = (icao: string) => nameByIcao.get(icao) ?? icao;
   const coordsByIcao = new Map(fc.features.map((f) => [f.properties.icao, f.properties]));
+  // v0.48.0 (ISS-095): leg distance for the UI — same haversine as live-plane math; 0 if a coord is missing.
+  const legDistanceKm = (originIcao: string, destIcao: string) => {
+    const from = coordsByIcao.get(originIcao);
+    const to = coordsByIcao.get(destIcao);
+    return from && to ? haversineKm(from.lat, from.lon, to.lat, to.lon) : 0;
+  };
 
   // Analytic movement (v0.7.0): a flying plane's stored lat/lon/fuel are its
   // departure values — live position and fuel are pure functions of the clock.
@@ -162,6 +170,7 @@ export async function getStateSnapshot(): Promise<StateSnapshot> {
       cargoCount: p.cargoCount,
       weightKg: p.weightKg,
       special: p.special,
+      distanceKm: legDistanceKm(p.originIcao, p.destIcao), // v0.48.0 (ISS-095)
       deadlineSimTime: p.deadlineSimTime,
       status: p.status,
       planeId: p.planeId,