重构：Wails v3 迁移 + 前端目录规范化 + Sidebar滚动优化

- web/ → frontend/ 目录重命名（Wails v3 标准结构）
- main.go: Middleware 修复 custom.js 404 + DevTools 延迟启动
- Sidebar: 收藏夹内部独立滚动 + 帮助区块固定底部
- useFavorites.ts: longPressTimer const→let 修复 TypeError
- App.vue: Arco Tabs padding-top 覆盖
- build: config.yml / Taskfile.yml 对齐官方模板，devtools build tag
- 新增 v3 bindings、vite.config.js、跨平台构建配置

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

frontend/src/api/transport.ts

@@ -0,0 +1,71 @@
+/**
+ * 文件系统传输层接口
+ * 本地模式走 Wails IPC，远程模式走 HTTP REST API
+ * Composable 和组件不感知底层差异
+ */
+
+export type FileItem = {
+  name: string
+  path: string
+  size: number
+  size_str?: string
+  is_dir: boolean
+  mod_time?: string
+  mode?: string
+}
+
+export type FileOperationResult = {
+  path: string
+  name: string
+  size: number
+  size_str?: string
+  is_dir: boolean
+  mod_time?: string
+  mode?: string
+  old_path?: string
+  deleted?: boolean
+}
+
+export type DetectTypeResult = {
+  extension: string
+  category: string
+  mime_type: string
+  confidence: number
+}
+
+export interface FsTransport {
+  // 文件列表与信息
+  listDir(path: string): Promise<FileItem[]>
+  getFileInfo(path: string): Promise<Record<string, any>>
+
+  // 文件读写
+  readFile(path: string): Promise<string>
+  writeFile(path: string, content: string): Promise<void>
+  saveBase64File(path: string, content: string): Promise<void>
+
+  // 文件操作
+  createFile(dirPath: string, filename: string): Promise<FileOperationResult>
+  createDir(parentPath: string, dirname: string): Promise<FileOperationResult>
+  deletePath(path: string): Promise<FileOperationResult>
+  renamePath(oldPath: string, newPath: string): Promise<FileOperationResult>
+
+  // ZIP 操作（Wave 3）
+  listZipContents(zipPath: string): Promise<FileItem[]>
+  extractFileFromZip(zipPath: string, filePath: string): Promise<string>
+  extractFileFromZipToTemp(zipPath: string, filePath: string): Promise<string>
+  getZipFileInfo(zipPath: string, filePath: string): Promise<FileItem>
+
+  // 系统操作
+  openPath(path: string): Promise<void>
+  getFileServerURL(): Promise<string>
+  getPreviewToken(): string
+  resolveShortcut(lnkPath: string): Promise<any>
+  detectFileTypeByContent(path: string): Promise<DetectTypeResult>
+  getCommonPaths(): Promise<Record<string, string>>
+
+  // 回收站（Wave 3）
+  getRecycleBinEntries(): Promise<any[]>
+  restoreFromRecycleBin(path: string): Promise<void>
+  deletePermanently(path: string): Promise<void>
+  emptyRecycleBin(): Promise<void>
+}