Tech: Self-Hosting Leaflet + Image-Sitemap

- Leaflet 1.9.4 + Markercluster 1.5.3 von unpkg.com lokal nach assets/vendor/leaflet/
  Spart externen DNS-Lookup, gibt Cache-Kontrolle, kein Third-Party-Call
  Inkl. marker/layers Bilder fuer Default-Marker
- preconnect zu unpkg.com aus 8 Seiten entfernt (nicht mehr noetig)
- sitemap.xml: image-Sitemap erweitert
  Pro URL og-image + Logo, Hauptseite zusaetzlich handshake
  Namespace xmlns:image hinzugefuegt

assets/vendor/leaflet/MarkerCluster.Default.css

@@ -0,0 +1,60 @@
+.marker-cluster-small {
+	background-color: rgba(181, 226, 140, 0.6);
+	}
+.marker-cluster-small div {
+	background-color: rgba(110, 204, 57, 0.6);
+	}
+
+.marker-cluster-medium {
+	background-color: rgba(241, 211, 87, 0.6);
+	}
+.marker-cluster-medium div {
+	background-color: rgba(240, 194, 12, 0.6);
+	}
+
+.marker-cluster-large {
+	background-color: rgba(253, 156, 115, 0.6);
+	}
+.marker-cluster-large div {
+	background-color: rgba(241, 128, 23, 0.6);
+	}
+
+	/* IE 6-8 fallback colors */
+.leaflet-oldie .marker-cluster-small {
+	background-color: rgb(181, 226, 140);
+	}
+.leaflet-oldie .marker-cluster-small div {
+	background-color: rgb(110, 204, 57);
+	}
+
+.leaflet-oldie .marker-cluster-medium {
+	background-color: rgb(241, 211, 87);
+	}
+.leaflet-oldie .marker-cluster-medium div {
+	background-color: rgb(240, 194, 12);
+	}
+
+.leaflet-oldie .marker-cluster-large {
+	background-color: rgb(253, 156, 115);
+	}
+.leaflet-oldie .marker-cluster-large div {
+	background-color: rgb(241, 128, 23);
+}
+
+.marker-cluster {
+	background-clip: padding-box;
+	border-radius: 20px;
+	}
+.marker-cluster div {
+	width: 30px;
+	height: 30px;
+	margin-left: 5px;
+	margin-top: 5px;
+
+	text-align: center;
+	border-radius: 15px;
+	font: 12px "Helvetica Neue", Arial, Helvetica, sans-serif;
+	}
+.marker-cluster span {
+	line-height: 30px;
+	}