clouds3d-only cleanup: drop Vanta/three.js/clouds2d, real-sky fixes, settlement lights, dynamic location anchor

default.conf

@@ -8,6 +8,13 @@ server {
         try_files $uri $uri/ =404;
     }
 
+    # The background page runs as an iframe on other origins; a stray
+    # favicon request must not log 404s.
+    location = /favicon.ico {
+        return 204;
+        access_log off;
+    }
+
     # CORS proxy for Carto basemaps (place names, OSM-derived).
     # URL format: /carto/voyager/{z}/{x}/{y}.png
     location ^~ /carto/ {
@@ -37,6 +44,17 @@ server {
         add_header Access-Control-Max-Age 86400 always;
     }
 
+    # CORS proxy for Mapzen/TILEZEN terrain-RGB "terrarium" elevation
+    # tiles (Copernicus DEM). URL format: /terrarium/{z}/{x}/{y}.png
+    location ^~ /terrarium/ {
+        resolver 1.1.1.1 8.8.8.8 ipv6=off valid=300s;
+        proxy_pass https://s3.amazonaws.com/elevation-tiles-prod/terrarium/;
+        proxy_ssl_server_name on;
+        proxy_set_header Host s3.amazonaws.com;
+        proxy_set_header User-Agent "Mozilla/5.0 (compatible; tile-proxy)";
+        add_header Access-Control-Allow-Origin "*" always;
+    }
+
     # CORS preflight handler
     location ~* \.(png|jpg)$ {
         if ($request_method = 'OPTIONS') {