refactor: 全面代码质量提升 — StringList→string[], strict 模式, 死代码清理

架构重构:
- StringList 类替换为不可变 string[]（消除 dataVersion hack，Zustand 自然检测变化）
- UndoRedoManager.undo/redo 返回新数组而非原地修改
- 删除 dataVersion 字段和 _bumpVersion()
- 启用 TypeScript strict 模式

死代码清理:
- 删除 string-list.ts, string-list.test.ts, use-path-validation.ts
- Rust AppError 保留供未来使用

功能修复:
- importFromJson 添加 try/catch
- handleClean 使用真实格式验证替代 () => true
- savePaths 保存前调用 backup_registry，处理部分保存失败
- importFromJson 校验非 object 类型输入

i18n 完善:
- MergePreview/StatusBar 硬编码中文 → t() 调用
- 新增 merge.* 和 status.* 翻译键

Rust 改进:
- registry.rs 抽取 load_paths/save_paths 通用函数，消除重复
- registry 新增 6 个单元测试（split/join/roundtrip）
- backup.rs 时间戳加毫秒防覆盖，回退路径改为 home_dir

元数据:
- package.json 名称→patheditor, 版本→4.0.0
- 新增 CHANGELOG.md
- 移除 UndoRedoButtons 废弃注释
- tsconfig 添加 strict:true

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/components/path-list/PathTable.tsx

@@ -12,8 +12,6 @@ interface PathRow {
 }
 
 export function PathTable({ tabId }: PathTableProps) {
-  const dataVersion = useAppStore((s) => s.dataVersion);
-  void dataVersion; // 订阅版本号强制重渲染
   const sysPaths = useAppStore((s) => s.sysPaths);
   const userPaths = useAppStore((s) => s.userPaths);
   const searchQuery = useAppStore((s) => s.searchQuery);
@@ -31,11 +29,11 @@ export function PathTable({ tabId }: PathTableProps) {
 
   // 过滤搜索
   const filtered = useMemo<PathRow[]>(() => {
-    if (!searchQuery) return paths.all.map((p, i) => ({ path: p, index: i }));
+    if (!searchQuery) return paths.map((p, i) => ({ path: p, index: i }));
     const q = searchQuery.toLowerCase();
     const result: PathRow[] = [];
     for (let i = 0; i < paths.length; i++) {
-      const p = paths.get(i)!;
+      const p = paths[i];
       if (p.toLowerCase().includes(q)) result.push({ path: p, index: i });
     }
     return result;
@@ -44,7 +42,7 @@ export function PathTable({ tabId }: PathTableProps) {
   // 异步验证未缓存的路径
   useEffect(() => {
     let cancelled = false;
-    const allPaths = paths.all;
+    const allPaths = paths;
 
     // 找出未缓存的路径
     const toValidate = allPaths.filter((p) => !validationCache.has(p));
@@ -81,7 +79,7 @@ export function PathTable({ tabId }: PathTableProps) {
   // 异步展开环境变量（用于 tooltip）
   useEffect(() => {
     let cancelled = false;
-    const toExpand = paths.all.filter(
+    const toExpand = paths.filter(
       (p) => p.includes('%') && !expandedCache.has(p),
     );
     if (toExpand.length === 0) return;
@@ -146,7 +144,7 @@ export function PathTable({ tabId }: PathTableProps) {
       if (!isActive) return;
       window.dispatchEvent(
         new CustomEvent('path-dblclick', {
-          detail: { index: realIndex, path: paths.get(realIndex) },
+          detail: { index: realIndex, path: paths[realIndex] },
         }),
       );
     },