Fix scroll-to-factcheck: disable GridStack animation during incident switch

Remove grid-stack-animate class before rendering to prevent CSS
transitions from causing browser scroll-follow to repositioned tiles.
Re-enable animation after content is loaded and scroll is reset.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/static/js/app.js

@@ -632,22 +632,24 @@ const App = {
         this.closeRefreshHistory();
         this.currentIncidentId = id;
         localStorage.setItem('selectedIncidentId', id);
-        // SR-Announcement
-        // Scroll komplett blockieren bevor irgendetwas gerendert wird
-        var mc = document.getElementById("main-content");
-        mc.style.overflow = "hidden";
-        mc.scrollTop = 0;
         const inc = this.incidents.find(i => i.id === id);
         if (inc) this._announceForSR('Lage ausgewählt: ' + inc.title);
         this.renderSidebar();
 
+        var mc = document.getElementById("main-content");
+        mc.scrollTop = 0;
+
         document.getElementById('empty-state').style.display = 'none';
         document.getElementById('incident-view').style.display = 'flex';
 
+        // GridStack-Animation temporaer deaktivieren um Scroll-Sprung zu verhindern
+        var gridEl = document.querySelector('.grid-stack');
+        if (gridEl) gridEl.classList.remove('grid-stack-animate');
+
         // gridstack-Layout initialisieren (einmalig)
         if (typeof LayoutManager !== 'undefined') LayoutManager.init();
 
-        // Refresh-Status für diese Lage wiederherstellen
+        // Refresh-Status fuer diese Lage wiederherstellen
         const isRefreshing = this._refreshingIncidents.has(id);
         this._updateRefreshButton(isRefreshing);
         if (isRefreshing) {
@@ -656,10 +658,14 @@ const App = {
             UI.hideProgress();
         }
 
-        mc.scrollTop = 0;
         await this.loadIncidentDetail(id);
+
+        // Zum Header scrollen und Animation wieder aktivieren
         mc.scrollTop = 0;
-        setTimeout(() => { mc.scrollTop = 0; mc.style.overflow = ""; }, 500);
+        requestAnimationFrame(() => {
+            mc.scrollTop = 0;
+            if (gridEl) gridEl.classList.add('grid-stack-animate');
+        });