fix: home time card fallback when no catalog

app/src/main/assets/h5/js/pages/home.js

@@ -10,9 +10,15 @@ window.updateHomeCards = async function () {
   try {
     catalog = JSON.parse(await bridge.call('fetchCards'));
   } catch (e) {
-    // 桥接不可用（如未接线）时降级为内置时间卡
-    // Degrade to builtin time card when the bridge is unavailable (e.g. not wired yet)
-    catalog = [{ id: 'time', priority: 0, enabled: true }];
+    // 桥接不可用（如未接线）时按空目录处理
+    // Treat bridge failure as an empty catalog
+    catalog = [];
+  }
+  if (!Array.isArray(catalog)) catalog = [];
+  // 兜底：无目录或缺失 time 卡时补内置大字时间卡，保证首页始终有时间卡
+  // Fallback: prepend builtin big time card when the catalog is empty or missing the time card
+  if (!catalog.some((c) => c.id === 'time')) {
+    catalog.push({ id: 'time', name: '大字时间', priority: 0 });
   }
   const cols = cards.layout(catalog);
   cols.forEach((ids, i) => {