fix: anchor hop disambiguation from sender origin, not just observer

resolve-hops now accepts originLat/originLon params. Forward pass
starts from sender position so first ambiguous hop resolves to the
nearest node to the sender, not the observer.

public/index.html

@@ -82,7 +82,7 @@
   <script src="roles.js?v=1774080000"></script>
   <script src="app.js?v=1774052279"></script>
   <script src="home.js?v=1774042199"></script>
-  <script src="packets.js?v=1774057771"></script>
+  <script src="packets.js?v=1774059560"></script>
   <script src="map.js?v=1774055877" onerror="console.error('Failed to load:', this.src)"></script>
   <script src="channels.js?v=1774050030" onerror="console.error('Failed to load:', this.src)"></script>
   <script src="nodes.js?v=1774050030" onerror="console.error('Failed to load:', this.src)"></script>

public/packets.js

@@ -927,7 +927,11 @@
         try {
           const obsId = obsName(pkt.observer_id);
           const observerParam = obsId ? '&observer=' + encodeURIComponent(obsId) : '';
-          const resp = await fetch('/api/resolve-hops?hops=' + encodeURIComponent(pathHops.join(',')) + observerParam);
+          // Anchor disambiguation from sender's location if known (e.g. ADVERT lat/lon)
+          const senderLat = decoded.lat || decoded.latitude;
+          const senderLon = decoded.lon || decoded.longitude;
+          const originParam = (senderLat != null && senderLon != null) ? `&originLat=${senderLat}&originLon=${senderLon}` : '';
+          const resp = await fetch('/api/resolve-hops?hops=' + encodeURIComponent(pathHops.join(',')) + observerParam + originParam);
           const data = await resp.json();
           // Pass full pubkeys (server-disambiguated) to map, falling back to short prefix
           const resolvedKeys = pathHops.map(h => {

server.js

@@ -1559,6 +1559,11 @@ app.get('/api/analytics/hash-sizes', (req, res) => {
 app.get('/api/resolve-hops', (req, res) => {
   const hops = (req.query.hops || '').split(',').filter(Boolean);
   const observerId = req.query.observer || null;
+  // Origin anchor: sender's lat/lon for forward-pass disambiguation.
+  // Without this, the first ambiguous hop falls through to the backward pass
+  // which anchors from the observer — wrong when sender and observer are far apart.
+  const originLat = req.query.originLat ? parseFloat(req.query.originLat) : null;
+  const originLon = req.query.originLon ? parseFloat(req.query.originLon) : null;
   if (!hops.length) return res.json({ resolved: {} });
 
   const allNodes = db.db.prepare('SELECT public_key, name, lat, lon FROM nodes WHERE name IS NOT NULL').all();
@@ -1623,7 +1628,7 @@ app.get('/api/resolve-hops', (req, res) => {
   const dist = (lat1, lon1, lat2, lon2) => Math.sqrt((lat1 - lat2) ** 2 + (lon1 - lon2) ** 2);
 
   // Forward pass: resolve each ambiguous hop using previous hop's position
-  let lastPos = null;
+  let lastPos = (originLat != null && originLon != null) ? { lat: originLat, lon: originLon } : null;
   for (let hi = 0; hi < hops.length; hi++) {
     const hop = hops[hi];
     if (hopPositions[hop]) {