feat: add tree view mode for host list with sorting and persistence

- Add tree view mode alongside existing grid and list views
- Implement hierarchical display of hosts organized by groups
- Add expand/collapse all controls with Chinese translations
- Support all sorting modes (A-Z, Z-A, newest, oldest) in tree view
- Persist expand/collapse state across view switches and app restarts
- Hide Groups section in tree view to avoid duplication
- Display ungrouped hosts at root level instead of "General" group
- Add missing delete group dialog with proper translations
- Maintain full functionality: search, filtering, drag-drop, context menus

Technical changes:
- Create HostTreeView component with TreeNode recursive structure
- Add useTreeExpandedState hook for persistent state management
- Extend ViewMode type to include "tree" option
- Add sortMode prop to enable dynamic sorting in tree structure
- Separate group tree logic for tree view vs other view modes
- Add comprehensive English and Chinese translations

application/state/useTreeExpandedState.ts

@@ -0,0 +1,47 @@
+import { useEffect, useState } from "react";
+import { localStorageAdapter } from "../../infrastructure/persistence/localStorageAdapter";
+
+export const useTreeExpandedState = (storageKey: string) => {
+  const [expandedPaths, setExpandedPaths] = useState<Set<string>>(() => {
+    const stored = localStorageAdapter.readString(storageKey);
+    if (stored) {
+      try {
+        const paths = JSON.parse(stored) as string[];
+        return new Set(paths);
+      } catch {
+        return new Set();
+      }
+    }
+    return new Set();
+  });
+
+  useEffect(() => {
+    const pathsArray = Array.from(expandedPaths);
+    localStorageAdapter.writeString(storageKey, JSON.stringify(pathsArray));
+  }, [storageKey, expandedPaths]);
+
+  const togglePath = (path: string) => {
+    const newExpanded = new Set(expandedPaths);
+    if (newExpanded.has(path)) {
+      newExpanded.delete(path);
+    } else {
+      newExpanded.add(path);
+    }
+    setExpandedPaths(newExpanded);
+  };
+
+  const expandAll = (allPaths: string[]) => {
+    setExpandedPaths(new Set(allPaths));
+  };
+
+  const collapseAll = () => {
+    setExpandedPaths(new Set());
+  };
+
+  return {
+    expandedPaths,
+    togglePath,
+    expandAll,
+    collapseAll,
+  };
+};