@mytec: iter10.4 ready for testing

frontend/src/components/map/Map.tsx

@@ -95,12 +95,13 @@ export default function MapView({ onMapClick, onEditSite, children }: MapViewPro
             zIndex={100}
           />
         )}
-        {/* Elevation color overlay (Stamen Terrain via Stadia Maps) */}
+        {/* Elevation color overlay (OpenTopoMap — no API key required) */}
         {showElevationOverlay && (
           <TileLayer
-            attribution='&copy; Stamen Design'
-            url="https://tiles.stadiamaps.com/tiles/stamen_terrain/{z}/{x}/{y}.png"
+            attribution='Map data: &copy; <a href="https://openstreetmap.org">OpenStreetMap</a>, SRTM | Style: &copy; <a href="https://opentopomap.org">OpenTopoMap</a> (<a href="https://creativecommons.org/licenses/by-sa/3.0/">CC-BY-SA</a>)'
+            url="https://{s}.tile.opentopomap.org/{z}/{x}/{y}.png"
             opacity={0.5}
+            maxZoom={17}
             zIndex={97}
           />
         )}