fix: use peer's current position for synced devices

- Load peer scanner positions from /api/peers
- Use peer's CURRENT position instead of stored position
- Ensures device positions update when peer scanner moves

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/rf_mapper/web/static/js/app.js

@@ -21,6 +21,9 @@ let manualPositions = {}; // { deviceId: { lat_offset, lon_offset } }
 // Device source scanner info - loaded from database (for synced devices)
 let deviceSources = {}; // { deviceId: { scanner_id, lat, lon } }
 
+// Peer scanner positions - loaded from /api/peers (live positions)
+let peerScanners = {}; // { scanner_id: { lat, lon, floor, name } }
+
 // Auto-scan state
 let autoScanEnabled = false;
 let autoScanPollInterval = null;
@@ -1062,9 +1065,10 @@ async function stopAutoScan() {
 
 // ========== Device Position Functions ==========
 
-// Load saved device positions and source scanner info from database
+// Load saved device positions, source scanner info, and peer positions
 async function loadDevicePositions() {
     try {
+        // Load device data
         const response = await fetch('/api/device/floors');
         if (response.ok) {
             const data = await response.json();
@@ -1078,6 +1082,22 @@ async function loadDevicePositions() {
                 console.log('[Sources] Loaded', Object.keys(deviceSources).length, 'device sources');
             }
         }
+
+        // Load peer scanner positions (live/current positions)
+        const peersResponse = await fetch('/api/peers');
+        if (peersResponse.ok) {
+            const peersData = await peersResponse.json();
+            peerScanners = {};
+            (peersData.peers || []).forEach(peer => {
+                peerScanners[peer.scanner_id] = {
+                    lat: peer.latitude,
+                    lon: peer.longitude,
+                    floor: peer.floor,
+                    name: peer.name
+                };
+            });
+            console.log('[Peers] Loaded', Object.keys(peerScanners).length, 'peer positions');
+        }
     } catch (error) {
         console.error('Error loading device positions:', error);
     }
@@ -1091,15 +1111,26 @@ function getDevicePosition(device, scannerLat, scannerLon, minDistanceM) {
     const sourceInfo = deviceSources[deviceId];
 
     // Determine which scanner position to use for this device
-    // If device was synced from another scanner, use that scanner's position
+    // If device was synced from another scanner, use that scanner's CURRENT position
     let baseLat = scannerLat;
     let baseLon = scannerLon;
     let isFromRemoteScanner = false;
+    let sourceScannerId = null;
 
-    if (sourceInfo && sourceInfo.lat != null && sourceInfo.lon != null) {
+    if (sourceInfo && sourceInfo.scanner_id) {
-        baseLat = sourceInfo.lat;
+        sourceScannerId = sourceInfo.scanner_id;
-        baseLon = sourceInfo.lon;
+        // Use peer's CURRENT position from peerScanners (not stored position)
-        isFromRemoteScanner = true;
+        const peerPos = peerScanners[sourceInfo.scanner_id];
+        if (peerPos && peerPos.lat != null && peerPos.lon != null) {
+            baseLat = peerPos.lat;
+            baseLon = peerPos.lon;
+            isFromRemoteScanner = true;
+        } else if (sourceInfo.lat != null && sourceInfo.lon != null) {
+            // Fallback to stored position if peer not in list
+            baseLat = sourceInfo.lat;
+            baseLon = sourceInfo.lon;
+            isFromRemoteScanner = true;
+        }
     }
 
     // If device has manual position, use it (relative to source scanner)
@@ -1109,7 +1140,7 @@ function getDevicePosition(device, scannerLat, scannerLon, minDistanceM) {
             lon: baseLon + customPos.lon_offset,
             isManual: true,
             isRemoteSource: isFromRemoteScanner,
-            sourceScanner: sourceInfo?.scanner_id || null
+            sourceScanner: sourceScannerId
         };
     }
 
@@ -1126,7 +1157,7 @@ function getDevicePosition(device, scannerLat, scannerLon, minDistanceM) {
         lon: baseLon + lonOffset,
         isManual: false,
         isRemoteSource: isFromRemoteScanner,
-        sourceScanner: sourceInfo?.scanner_id || null
+        sourceScanner: sourceScannerId
     };
 }
 
@@ -1232,9 +1263,16 @@ async function onMarkerDragEnd(marker, deviceId, scannerLat, scannerLon) {
     let baseLat = scannerLat;
     let baseLon = scannerLon;
 
-    if (sourceInfo && sourceInfo.lat != null && sourceInfo.lon != null) {
+    if (sourceInfo && sourceInfo.scanner_id) {
-        baseLat = sourceInfo.lat;
+        // Use peer's CURRENT position
-        baseLon = sourceInfo.lon;
+        const peerPos = peerScanners[sourceInfo.scanner_id];
+        if (peerPos && peerPos.lat != null && peerPos.lon != null) {
+            baseLat = peerPos.lat;
+            baseLon = peerPos.lon;
+        } else if (sourceInfo.lat != null && sourceInfo.lon != null) {
+            baseLat = sourceInfo.lat;
+            baseLon = sourceInfo.lon;
+        }
     }
 
     const latOffset = lngLat.lat - baseLat;