feat(v1.2): 体验升级 — 快捷键系统 + 标签拖拽 + SFTP拖拽上传 + 组件拆分 + 响应式

任务1: 全局快捷键管理器 — useKeyboardShortcuts hook
  Ctrl+Tab/Shift+Tab标签切换, Ctrl+1~9跳转, F11全屏, Ctrl+Shift+N新建标签

任务2: 标签拖拽排序 — tabStore.moveTab + TabBar HTML5 DnD
  不可变更新, 拖拽视觉反馈(opacity+指示线), 活跃标签底部accent-blue指示线

任务3: SFTP拖拽上传 + useSFTP调试清理
  FileListPanel拖拽覆盖层(Upload图标+虚线边框), 5个调试函数→createLogger,
  disconnect()正确调用IPC, 删除mock data

任务4: SFTP右键菜单完善 — 重命名/复制路径/属性/权限
  FilePropertiesDialog+ChmodDialog, sftpStat/sftpChmod IPC全栈实现

任务5-6: 侧边栏分组折叠动画 + 宽度可拖拽调整
  Grid 0fr→1fr折叠动画, ChevronRight旋转, resize handle 180~400px, settings记忆

任务7: 响应式布局 + 视觉优化V1~V5
  useMediaQuery hook, <800px侧边栏overlay模式, SFTP垂直堆叠, WelcomeView响应式grid

任务8: Loading/Skeleton骨架屏
  Skeleton/SkeletonLine/SkeletonCircle/SkeletonBlock + FileListSkeleton/SessionTreeSkeleton/TabContentSkeleton

任务9: 空状态设计
  EmptyState通用组件, SessionTree/FileListPanel/WelcomeView/SFTPView空状态引导

任务10: TerminalView组件拆分重构 711行→285行
  useTerminalConnection(300行) + useTerminalSearch(123行)
  + TerminalOverlay(98行) + TerminalSearchBar(74行)

33 files changed, 2682 insertions(+), 872 deletions(-)

electron/ipc/sftp.ipc.ts

@@ -15,6 +15,8 @@ export const SFTP_CHANNELS = {
   RENAME: 'sftp:rename',
   DELETE: 'sftp:delete',
   MKDIR: 'sftp:mkdir',
+  STAT: 'sftp:stat',
+  CHMOD: 'sftp:chmod',
   PROGRESS: 'sftp:progress',
 } as const
 
@@ -193,4 +195,46 @@ export function registerSFTPIPCHandlers(options: SFTPIPCOptions): void {
       return { success: false, error: error.message }
     }
   })
+
+  // SFTP stat
+  ipcMain.handle(SFTP_CHANNELS.STAT, async (
+    _event: IpcMainInvokeEvent,
+    sftpId: string,
+    filePath: string
+  ) => {
+    logHeader('📋 SFTP IPC STAT')
+    logInfo('sftpId', sftpId)
+    logInfo('filePath', filePath)
+
+    try {
+      const stats = await sshService.sftpStat(sftpId, filePath)
+      logSuccess(`Stat complete: ${stats.size} bytes`)
+      return { success: true, stats }
+    } catch (error: any) {
+      logError(`Stat failed: ${error.message}`)
+      return { success: false, error: error.message }
+    }
+  })
+
+  // SFTP chmod
+  ipcMain.handle(SFTP_CHANNELS.CHMOD, async (
+    _event: IpcMainInvokeEvent,
+    sftpId: string,
+    filePath: string,
+    mode: number
+  ) => {
+    logHeader('🔒 SFTP IPC CHMOD')
+    logInfo('sftpId', sftpId)
+    logInfo('filePath', filePath)
+    logInfo('mode', mode.toString(8))
+
+    try {
+      await sshService.sftpChmod(sftpId, filePath, mode)
+      logSuccess('Chmod complete')
+      return { success: true }
+    } catch (error: any) {
+      logError(`Chmod failed: ${error.message}`)
+      return { success: false, error: error.message }
+    }
+  })
 }

electron/preload.ts

@@ -25,6 +25,8 @@ const api = {
   sftpRename: (sftpId: string, oldPath: string, newPath: string) => ipcRenderer.invoke('sftp:rename', sftpId, oldPath, newPath),
   sftpDelete: (sftpId: string, path: string, isDirectory: boolean) => ipcRenderer.invoke('sftp:delete', sftpId, path, isDirectory),
   sftpMkdir: (sftpId: string, path: string) => ipcRenderer.invoke('sftp:mkdir', sftpId, path),
+  sftpStat: (sftpId: string, filePath: string) => ipcRenderer.invoke('sftp:stat', sftpId, filePath),
+  sftpChmod: (sftpId: string, filePath: string, mode: number) => ipcRenderer.invoke('sftp:chmod', sftpId, filePath, mode),
 
   // 端口转发
   sshForwardLocal: (connectionId: string, localPort: number, remoteHost: string, remotePort: number) =>

electron/services/ssh-service.ts

@@ -480,6 +480,56 @@ export class SSHService {
     })
   }
 
+  async sftpStat(sftpId: string, filePath: string): Promise<{
+    size: number
+    mode: number
+    mtime: number
+    atime: number
+    isDirectory: boolean
+    isFile: boolean
+    isSymbolicLink: boolean
+  }> {
+    const session = this.sftps.get(sftpId)
+    if (!session) {
+      throw new Error('SFTP session not found')
+    }
+
+    return new Promise((resolve, reject) => {
+      session.sftp.stat(filePath, (err, stats) => {
+        if (err) {
+          reject(err)
+          return
+        }
+        resolve({
+          size: stats.size,
+          mode: stats.mode,
+          mtime: stats.mtime,
+          atime: stats.atime,
+          isDirectory: stats.isDirectory(),
+          isFile: stats.isFile(),
+          isSymbolicLink: stats.isSymbolicLink(),
+        })
+      })
+    })
+  }
+
+  async sftpChmod(sftpId: string, filePath: string, mode: number): Promise<void> {
+    const session = this.sftps.get(sftpId)
+    if (!session) {
+      throw new Error('SFTP session not found')
+    }
+
+    return new Promise((resolve, reject) => {
+      session.sftp.chmod(filePath, mode, (err) => {
+        if (err) {
+          reject(err)
+          return
+        }
+        resolve()
+      })
+    })
+  }
+
   // 端口转发
   // ===== 本地端口转发 =====
   async forwardLocal(