Fix browser caching issue preventing live updates in device filter

Added cache-busting parameter to API URL to prevent browser from
serving stale cached responses. This ensures that device-specific
filters always show the most recent location data.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

index.html

@@ -377,7 +377,9 @@
 
         async function loadLocations() {
             try {
-                const response = await fetch(API_URL);
+                // Cache-Busting: füge Timestamp hinzu
+                const cacheBustedUrl = `${API_URL}?_t=${Date.now()}`;
+                const response = await fetch(cacheBustedUrl);
                 const data = await response.json();
 
                 allData = data;