fix render

src/app.js

@@ -2861,6 +2861,7 @@ function renderView() {
     themeLabel.textContent = t("ui.theme");
   }
 
+  try {
     switch (currentView) {
       case "dashboard":
         renderDashboard();
@@ -2898,6 +2899,17 @@ function renderView() {
       default:
         renderDashboard();
     }
+  } catch (error) {
+    console.error("renderView failed", error);
+    dom.view.innerHTML = `
+      <section class="panel">
+        <div class="panel-header"><h3>Render error</h3></div>
+        <div class="panel-body">
+          <p>${escapeHtml(error instanceof Error ? error.message : String(error))}</p>
+        </div>
+      </section>
+    `;
+  }
 
   updateHeaderState();
 }
@@ -3202,8 +3214,8 @@ function handleSessionTimerTick() {
 function renderDashboard() {
   const active = getActiveSession();
   const schedule = getScheduleDriftSummary();
-  const totalPassings = Object.values(state.resultsBySession).reduce(
+  const totalPassings = Object.values(state.resultsBySession || {}).reduce(
-    (sum, x) => sum + (x.passings?.length || 0),
+    (sum, x) => sum + (x?.passings?.length || 0),
     0
   );
   const backendUrl = getBackendUrl();