Unwrap great-circle arc longitudes across the antimeridian so routes don't chord across the map (ISS-120)

e2e/hover.spec.ts

@@ -171,6 +171,16 @@ async function fitToAirports(page: Page, icaos: string[]): Promise<void> {
     if (!f) throw new Error(`airport ${icao} not found in /api/airports`);
     return [f.properties.lon, f.properties.lat] as [number, number];
   });
+  // ISS-120 (v0.53.0): raw min/max bounds for a pair straddling ±180 span the WRONG side of the globe
+  // (−175…+174 covers the Atlantic, not the Pacific) — unwrap each point relative to its predecessor so
+  // the bounds follow the short arc across the date line. Non-crossing pairs are unchanged.
+  for (let i = 1; i < points.length; i++) {
+    let lon = points[i]![0];
+    const prev = points[i - 1]![0];
+    while (lon - prev > 180) lon -= 360;
+    while (prev - lon > 180) lon += 360;
+    points[i]![0] = lon;
+  }
   await page.evaluate((pts: [number, number][]) => {
     const m = (window as any).__flightMap;
     if (!m) throw new Error('map not ready');
@@ -217,8 +227,13 @@ const HOVER_ROUTE_EPS_DEG = 0.05; // ~5 km: above worst-case quantization at any
 
 async function expectHoverRoute(page: Page, fromIcao: string, toIcao: string): Promise<void> {
   const [from, to] = await Promise.all([airportLonLat(page, fromIcao), airportLonLat(page, toIcao)]);
-  const near = (a: [number, number], b: [number, number]) =>
-    Math.abs(a[0] - b[0]) <= HOVER_ROUTE_EPS_DEG && Math.abs(a[1] - b[1]) <= HOVER_ROUTE_EPS_DEG;
+  // ISS-120 (v0.53.0): antimeridian-crossing traces end UNWRAPPED — the dest-side endpoint is ≡ dest
+  // (mod 360) but sits at e.g. +184.9 instead of −175.1, so compare longitudes on the circle. For any
+  // two lons within ±180 of each other this equals the plain |Δlon| — existing routes are unaffected.
+  const near = (a: [number, number], b: [number, number]) => {
+    const dLon = Math.abs(a[0] - b[0]);
+    return Math.min(dLon, 360 - dLon) <= HOVER_ROUTE_EPS_DEG && Math.abs(a[1] - b[1]) <= HOVER_ROUTE_EPS_DEG;
+  };
   await expect.poll(async () => {
     const feats = (await renderedFeatures(page, ['hover-route'])) as Array<{ geometry?: { type: string; coordinates: [number, number][] } }>;
     // Features are plain objects with in-page-evaluated geometry (see renderedFeatures). The filter
@@ -344,6 +359,51 @@ test('hovering an open package highlights its endpoint airports', async ({ page
   }).toBe(0);
 });
 
+// ISS-120 (v0.53.0): Auckland → Fua'amotu (Tonga) — both in the world dataset, and their short great
+// circle crosses ±180 EASTWARD. Before the fix the arc's wrapped samples jumped +179.x → −179.x and
+// MapLibre connected them with a chord across the whole map; now the trace is one continuous line.
+test('hovering an antimeridian-crossing package draws one continuous trace, no chord across the map', async ({ page }) => {
+  test.setTimeout(300_000); // self-heal can take minutes after an interrupted run
+  await flyHomeViaApi(page);
+
+  const pkg = await createPackage(page, 'NZAA', 'NFTF');
+
+  await page.goto('/');
+  await waitForAirportCount(page);
+
+  const row = page.locator(`li[data-testid="open-package-${pkg.id}"]`);
+  await expect(row, 'the hook-created package appears in the list').toBeVisible({ timeout: 15_000 });
+
+  // fitToAirports unwraps crossing pairs (ISS-120) so both endpoints are in-viewport.
+  await fitToAirports(page, ['NZAA', 'NFTF']);
+
+  await row.hover();
+  await expectHoverRoute(page, 'NZAA', 'NFTF'); // endpoint check is mod-360 aware now (ISS-120)
+
+  // The regression itself: no rendered segment may contain a ±180 longitude jump — that was the chord.
+  await expect.poll(async () => {
+    const feats = (await renderedFeatures(page, ['hover-route'])) as Array<{ geometry?: { type: string; coordinates: [number, number][] } }>;
+    const segs = feats.filter(
+      (f): f is { geometry: { type: 'LineString'; coordinates: [number, number][] } } =>
+        !!f.geometry && f.geometry.type === 'LineString' && Array.isArray(f.geometry.coordinates) && f.geometry.coordinates.length >= 2,
+    );
+    if (!segs.length) return false; // none yet — keep polling
+    for (const s of segs) {
+      const c = s.geometry.coordinates;
+      for (let i = 1; i < c.length; i++) {
+        if (Math.abs(c[i]![0] - c[i - 1]![0]) >= 180) return false; // a wrapped jump — the chord bug is back
+      }
+    }
+    return true;
+  }, { timeout: 15_000, message: 'waiting for the hover-route trace to be continuous across the antimeridian' }).toBe(true);
+
+  await unhover(page);
+  await expect.poll(async () => (await renderedFeatures(page, ['hover-route'])).length, {
+    timeout: 15_000,
+    message: 'waiting for the hover route trace to clear after mouseleave',
+  }).toBe(0);
+});
+
 test('hovering an on-board cargo row draws its trace and keeps the plane halo', async ({ page }) => {
   test.setTimeout(300_000); // self-heal can take minutes after an interrupted run
   await flyHomeViaApi(page); // deterministic: the starter sits grounded at EDDF