fix(trash & sidebar): isolate trash view, sync list task counts in real-time, and fix restore/delete actions

src/components/layout/AppShell.tsx

@@ -116,7 +116,7 @@ export function AppShell({ user, isDemo = false }: AppShellProps) {
     return () => document.removeEventListener("checkflow:openCommandPalette", handler);
   }, []);
 
-  // Demo tasks filter & reconstruct hierarchical structure
+  // Task filter & reconstruct hierarchical structure for Demo and API modes
   useEffect(() => {
     if (isDemo) {
       const store = getDemoStore();
@@ -130,6 +130,23 @@ export function AppShell({ user, isDemo = false }: AppShellProps) {
           (t) => !t.isDeleted && t.listId === selectedListId && (showCompleted ? true : !t.completed)
         );
         setTasks(listTasks);
+      } else {
+        setTasks([]);
+      }
+    } else {
+      // Authenticated API mode
+      if (isTrashActive) {
+        setTasks([]);
+      } else if (selectedTag) {
+        fetch(`/api/tasks?tag=${encodeURIComponent(selectedTag)}&showCompleted=${showCompleted}`)
+          .then((r) => (r.ok ? r.json() : []))
+          .then((data) => setTasks(Array.isArray(data) ? data : []))
+          .catch((err) => console.error("Failed to load tag tasks", err));
+      } else if (selectedListId) {
+        fetch(`/api/tasks?listId=${selectedListId}&showCompleted=${showCompleted}`)
+          .then((r) => (r.ok ? r.json() : []))
+          .then((data) => setTasks(Array.isArray(data) ? data : []))
+          .catch((err) => console.error("Failed to load list tasks", err));
       }
     }
   }, [isDemo, selectedListId, isTrashActive, selectedTag, showCompleted, refreshKey]);
@@ -161,18 +178,25 @@ export function AppShell({ user, isDemo = false }: AppShellProps) {
 
   const handleTagSelect = useCallback((tagName: string | null) => {
     setIsTrashActive(false);
+    setSelectedListId(null);
     setSelectedTag(tagName);
     setSelectedTask(null);
     setSidebarOpen(false);
   }, []);
 
   const handleTrashSelect = useCallback(() => {
-    setIsTrashActive(true);
-    setSelectedTag(null);
     setSelectedListId(null);
+    setSelectedTag(null);
+    setIsTrashActive(true);
     setSelectedTask(null);
     setSidebarOpen(false);
-  }, []);
+    if (isDemo) {
+      const store = getDemoStore();
+      setTasks(getAllTrashTasks(store.tasks) as Task[]);
+    } else {
+      setTasks([]);
+    }
+  }, [isDemo]);
 
   // Update List Name
   const handleUpdateListName = async (id: string, newName: string) => {