Fix duplicate indicator addition by preventing multiple event listeners

Added eventListenersSet flag to track if event delegation has been setup.
Only call setupEventListeners() once during initial render to prevent
adding multiple event listeners that cause 'addIndicator' to be called
multiple times when clicking a button once.

This fixes the bug where one click adds 8 identical indicators.

src/api/dashboard/static/js/ui/indicators-panel-new.js

@@ -6,6 +6,7 @@ let configuringId = null;
 let searchQuery = '';
 let selectedCategory = 'all';
 let nextInstanceId = 1;
+let eventListenersSet = false;
 
 // Chart pane management
 let indicatorPanes = new Map();
@@ -153,7 +154,6 @@ export function renderIndicatorPanel() {
                     <div class="section-title">★ Favorites</div>
                     ${[...favoriteIds].map(id => {
                         const ind = available.find(a => {
-                            // Find matching indicator by type
                             return a.type === id || (activeIndicators.find(ai => ai.id === id)?.type === '');
                         });
                         if (!ind) return '';
@@ -187,7 +187,12 @@ export function renderIndicatorPanel() {
         </div>
     `;
     
+    // Only setup event listeners once
+    if (!eventListenersSet) {
         setupEventListeners();
+        eventListenersSet = true;
+    }
+}
 }
 
 function renderIndicatorItem(indicator, isFavorite) {