perf: lighthouse optimizations - inline critical CSS, lazy-load routes, WebP images, fix CLS and contrast

js/components/search-box.js

@@ -336,6 +336,7 @@ class SearchBox extends HTMLElement {
                         <path d="M21 10c0 7-9 13-9 13s-9-6-9-13a9 9 0 0 1 18 0z"></path>
                         <circle cx="12" cy="10" r="3"></circle>
                     </svg>
+                    <label for="country-select-mobile" class="sr-only">${t('search.currentLocation')}</label>
                     <select id="country-select-mobile">
                         <option value="current" ${this.useCurrentLocation ? 'selected' : ''}>
                             📍 ${t('search.currentLocation')}