Add NHC forecast track to hurricane click-to-map

- Parse NHC forecast advisory text (FORECAST VALID / OUTLOOK VALID lines)
  to extract real forecast positions at 9–117h intervals with wind speeds
- Render forecast track as dashed line + clickable dots (wind on click)
- Auto-fit map bounds to show the full 5-day track after loading
- Fix buildStyle to use OpenFreeMap vector tile URLs without API key

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/server.js

@@ -514,17 +514,82 @@ app.get('/api/hurricanes', async (_req, res) => {
 app.get('/api/hurricanes/track', async (req, res) => {
   const { stormId } = req.query;
   if (!stormId || !/^[a-z]{2}\d{6}$/i.test(stormId)) {
-    return res.json({ type: 'FeatureCollection', features: [] });
+    return res.json({ lin: null, pts: null, pgn: null });
   }
   try {
-    const id = stormId.toUpperCase();
-    const r = await fetchWithRetry(
-      `https://www.nhc.noaa.gov/gis/json/${id}_5day_lin.json`,
-      { attempts: 2, timeoutMs: 8000, fetchOptions: { headers: { 'User-Agent': 'weather-app-v2 (nate@necloud.us)', Accept: 'application/json' } } }
-    );
-    res.json(await r.json());
-  } catch {
-    res.json({ type: 'FeatureCollection', features: [] });
+    const sid = stormId.toLowerCase();
+    let storm = (hCache.data?.storms || []).find(s => s.id?.toLowerCase() === sid);
+    if (!storm) {
+      const r = await fetchWithRetry('https://www.nhc.noaa.gov/CurrentStorms.json', {
+        attempts: 2, timeoutMs: 10000, fetchOptions: { headers: { 'User-Agent': 'weather-app-v2 (nate@necloud.us)' } }
+      });
+      storm = ((await r.json()).activeStorms || []).find(s => s.id?.toLowerCase() === sid);
+    }
+    const advisoryUrl = storm?.forecastAdvisory?.url;
+    if (!advisoryUrl) return res.json({ lin: null, pts: null, pgn: null });
+
+    const r = await fetchWithRetry(advisoryUrl, {
+      attempts: 2, timeoutMs: 8000,
+      fetchOptions: { headers: { 'User-Agent': 'weather-app-v2 (nate@necloud.us)' } }
+    });
+    const text = (await r.text()).replace(/<[^>]+>/g, '');
+
+    const issuanceMs = new Date(storm?.forecastAdvisory?.issuance || storm?.lastUpdate || Date.now()).getTime();
+    const issueDate = new Date(issuanceMs);
+
+    function parseDDHHZ(ddHH) {
+      const day = parseInt(ddHH.slice(0, 2));
+      const hour = parseInt(ddHH.slice(2, 4));
+      const d = new Date(issueDate);
+      d.setUTCDate(day);
+      d.setUTCHours(hour, 0, 0, 0);
+      if (d < issueDate) d.setUTCMonth(d.getUTCMonth() + 1);
+      return Math.round((d - issueDate) / 3600000);
+    }
+
+    const positions = [];
+
+    // Current position from "CENTER LOCATED NEAR LL.LN LLL.LW AT DD/HHMMZ"
+    const initM = text.match(/CENTER LOCATED NEAR\s+(\d+\.?\d*)([NS])\s+(\d+\.?\d*)([EW])/);
+    const curWindM = text.match(/MAX SUSTAINED WINDS\s+(\d+)\s+KT/);
+    if (initM) {
+      positions.push({
+        tau: 0,
+        lat: parseFloat(initM[1]) * (initM[2] === 'S' ? -1 : 1),
+        lon: parseFloat(initM[3]) * (initM[4] === 'W' ? -1 : 1),
+        windKt: curWindM ? parseInt(curWindM[1]) : 0,
+        type: storm?.classification || 'TS',
+      });
+    }
+
+    // "FORECAST VALID DD/HHMMZ LL.LN LLL.LW" and "OUTLOOK VALID ..." lines
+    const fcstRe = /(?:FORECAST|OUTLOOK)\s+VALID\s+(\d{2})\/(\d{2})\d{2}Z\s+(\d+\.?\d*)([NS])\s+(\d+\.?\d*)([EW])/g;
+    let m;
+    while ((m = fcstRe.exec(text)) !== null) {
+      const tau = parseDDHHZ(m[1] + m[2]);
+      const lat = parseFloat(m[3]) * (m[4] === 'S' ? -1 : 1);
+      const lon = parseFloat(m[5]) * (m[6] === 'W' ? -1 : 1);
+      const windM = text.substring(m.index).match(/MAX WIND\s+(\d+)\s+KT/);
+      positions.push({ tau, lat, lon, windKt: windM ? parseInt(windM[1]) : 0, type: storm?.classification || 'TS' });
+    }
+
+    if (!positions.length) return res.json({ lin: null, pts: null, pgn: null });
+
+    const coords = positions.map(p => [p.lon, p.lat]);
+    const ptFeatures = positions.map(p => ({
+      type: 'Feature',
+      geometry: { type: 'Point', coordinates: [p.lon, p.lat] },
+      properties: { TAU: p.tau, MAXWIND: p.windKt, TCDVLP: p.type },
+    }));
+
+    res.json({
+      lin: { type: 'FeatureCollection', features: [{ type: 'Feature', geometry: { type: 'LineString', coordinates: coords }, properties: {} }] },
+      pts: { type: 'FeatureCollection', features: ptFeatures },
+      pgn: null,
+    });
+  } catch (e) {
+    console.error('[track] error:', e.message);
+    res.json({ lin: null, pts: null, pgn: null });
   }
 });