Use OpenStreetMap tiles for APRS map

Switch from CartoDB dark tiles to standard OpenStreetMap tiles
which show roads and more detail for tracking APRS stations.

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

templates/index.html

@@ -6131,8 +6131,9 @@
 
             aprsMap = L.map('aprsMap').setView([initialLat, initialLon], initialZoom);
 
-            L.tileLayer('https://{s}.basemaps.cartocdn.com/dark_all/{z}/{x}/{y}{r}.png', {
-                attribution: '© OpenStreetMap contributors © CARTO',
+            // OpenStreetMap with roads - better for APRS station tracking
+            L.tileLayer('https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
+                attribution: '&copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors',
                 maxZoom: 19
             }).addTo(aprsMap);