Preload and lazy-load info modal banner

Improve load performance and perceived responsiveness for the info modal banner image. Adds loading="lazy" to the banner image in InfoModal.vue and implements preloadBannerImage in MapView.vue which preloads props.bannerImageUrl. The info button now triggers preloading on @mouseenter to reduce delay when opening the modal.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: SableRaf

pcd-website/src/components/InfoModal.vue

@@ -66,6 +66,7 @@ onUnmounted(() => {
           class="info-modal-banner"
           alt=""
           aria-hidden="true"
+          loading="lazy"
         />
         <div class="info-modal-body">
           <h2 class="info-modal-title">{{ t('nav.info_modal_title') }}</h2>

pcd-website/src/components/MapView.vue

@@ -23,6 +23,11 @@ const selectedNode = ref<Node | null>(null);
 const listOpen = ref(false);
 const infoModalOpen = ref(false);
 
+function preloadBannerImage() {
+  const url = props.bannerImageUrl;
+  if (url) new Image().src = url;
+}
+
 let mapInstance: import('leaflet').Map | null = null;
 let leafletRef: typeof import('leaflet') | null = null;
 const markerMap = new Map<string, import('leaflet').Marker>();
@@ -634,6 +639,7 @@ onUnmounted(() => {
     <button
       id="info-btn"
       :aria-label="t('nav.info_button_label')"
+      @mouseenter="preloadBannerImage"
       @click="infoModalOpen = true"
     >i</button>
   </div>