Add popup persistence and update project docs

- Popups now stay open during live BT tracking updates
- Track open popup device ID and restore after marker refresh
- Update TASKS.md, TODO.md, PROJECT.md, ROADMAP.md
- Mark position smoothing, floor persistence as complete

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

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

@@ -101,6 +101,7 @@ let map3dDeviceData = {};  // Store device info for popup display
 let currentFloor = 'all';  // Will be set to building.currentFloor on init
 let map3dInitialized = false;
 let map3dLoaded = false;
+let openPopupDeviceId = null;  // Track which device popup is open
 
 // Initialize on DOM ready
 document.addEventListener('DOMContentLoaded', () => {
@@ -1127,6 +1128,14 @@ function update3DMarkers() {
         return;
     }
 
+    // Save currently open popup before removing markers
+    let savedPopupDeviceId = openPopupDeviceId;
+    map3dMarkers.forEach(m => {
+        if (m.getPopup() && m.getPopup().isOpen()) {
+            savedPopupDeviceId = m._deviceId || savedPopupDeviceId;
+        }
+    });
+
     // Remove existing markers
     map3dMarkers.forEach(m => m.remove());
     map3dMarkers = [];
@@ -1215,6 +1224,9 @@ function update3DMarkers() {
             .setLngLat([lon + lonOffset, lat + latOffset])
             .setPopup(popup)
             .addTo(map3d);
+        marker._deviceId = wifiDeviceId;
+        popup.on('open', () => { openPopupDeviceId = wifiDeviceId; });
+        popup.on('close', () => { if (openPopupDeviceId === wifiDeviceId) openPopupDeviceId = null; });
         map3dMarkers.push(marker);
     });
 
@@ -1266,9 +1278,20 @@ function update3DMarkers() {
             .setLngLat([lon + lonOffset, lat + latOffset])
             .setPopup(popup)
             .addTo(map3d);
+        marker._deviceId = btDeviceId;
+        popup.on('open', () => { openPopupDeviceId = btDeviceId; });
+        popup.on('close', () => { if (openPopupDeviceId === btDeviceId) openPopupDeviceId = null; });
         map3dMarkers.push(marker);
     });
 
+    // Reopen saved popup if device still exists
+    if (savedPopupDeviceId) {
+        const markerToOpen = map3dMarkers.find(m => m._deviceId === savedPopupDeviceId);
+        if (markerToOpen && markerToOpen.getPopup()) {
+            markerToOpen.togglePopup();
+        }
+    }
+
     console.log('update3DMarkers:', map3dMarkers.length, 'DOM markers at floor', scannerFloor);
 
     // Update floor device count