fix: refine earth settings modal and hud interactions

frontend/public/earth/js/legend.js

@@ -49,6 +49,9 @@ function renderLegend(mode) {
 
   const config = LEGEND_MODES[mode] || LEGEND_MODES.cables;
   const items = legendItemsByMode[mode] || [];
+  const titleEl = legend.querySelector(".legend-title");
+  const listEl = legend.querySelector(".legend-list");
+  if (!titleEl || !listEl) return;
   const itemsHtml = items
     .map(
       (item) => `
@@ -60,8 +63,6 @@ function renderLegend(mode) {
     )
     .join("");
 
-  legend.innerHTML = `
-    <h3 class="legend-title hud-panel-title">${config.title}</h3>
-    <div class="legend-list">${itemsHtml}</div>
-  `;
+  titleEl.textContent = config.title;
+  listEl.innerHTML = itemsHtml;
 }