feat(remote): 文件传输改用Electron IPC通道

- 主进程新增4个IPC handler处理远程文件操作
- 前端通过IPC调用而非浏览器fetch访问远程API
- Remote服务新增3003端口专门处理文件传输
- 上传使用文件路径方案，下载使用保存对话框方案

src/modules/remote/components/file-transfer/FileTransferPage.tsx

@@ -1,6 +1,6 @@
 import React, { useState, useCallback, useRef, useEffect } from 'react'
 import type { FileItem } from '@/lib/api'
-import { type RemoteFileItem, uploadFileToRemote, downloadFileFromRemote, fetchSystemFileContent } from '../../api'
+import { type RemoteFileItem, uploadFileToRemote, downloadFileFromRemote } from '../../api'
 import { type TransferItem } from '../../types'
 import { LocalFilePanel } from './LocalFilePanel'
 import { RemoteFilePanel } from './RemoteFilePanel'
@@ -40,10 +40,7 @@ export const FileTransferPage: React.FC<FileTransferPageProps> = ({ serverHost,
     setTransfers((prev) => [...prev, newTransfer])
 
     try {
-      const blob = await fetchSystemFileContent(localSelected.path)
-      const file = new File([blob], localSelected.name, { type: blob.type })
-
-      await uploadFileToRemote(serverHost, port, file, remotePath, password, (progress) => {
+      await uploadFileToRemote(serverHost, port, localSelected.path, remotePath, password, (progress) => {
         setTransfers((prev) =>
           prev.map((t) => (t.id === transferId ? { ...t, progress } : t))
         )
@@ -67,7 +64,7 @@ export const FileTransferPage: React.FC<FileTransferPageProps> = ({ serverHost,
     } finally {
       setTransferring(false)
     }
-  }, [localSelected, serverHost, port])
+  }, [localSelected, serverHost, port, remotePath, password])
 
   const handleDownload = useCallback(async () => {
     if (!remoteSelected) return