UI-tests und fixes aus tests

public/js/modules/caldav.js

@@ -238,6 +238,7 @@ $('cal-sync')?.addEventListener('click', () => triggerSync());
 // Auto-sync throttle
 let lastAutoSync = 0;
 export function autoSync() {
+    if (window._testRunning) return;
     const now = Date.now();
     if (now - lastAutoSync < 60000) return;
     lastAutoSync = now;
@@ -288,3 +289,6 @@ export function startBackgroundSync() {
     backgroundSync();
     bgSyncInterval = setInterval(backgroundSync, 45000); // every 45 seconds
 }
+export function stopBackgroundSync() {
+    if (bgSyncInterval) { clearInterval(bgSyncInterval); bgSyncInterval = null; }
+}