install.ps1: powershell script might download release version faster by few lines changes in windows installation script

Hi, this is ancient bug of powershell itself, related to: https://github.com/PowerShell/PowerShell/issues/2138
tl;dr: very slow downloading when used Invoke-WebRequest in powershell. That why its so slow to download binary from github.

Report & Suggestion about:

irm https://code.kimi.com/kimi-code/install.ps1 | iex

try {
  $binaryUrl = "$KimiBinaryBase/$version/$filename"
  $tmpBinary = Join-Path $tmp $filename
  Write-Step "Downloading $binaryUrl"
  Invoke-WebRequest -Uri $binaryUrl -OutFile $tmpBinary

  Write-Step "Verifying checksum"
  Test-Sha256 $tmpBinary $checksum

Windows 11, latest build.
Replace with: Start-BitsTransfer -Source

And this will help a lot to speedup downloading cli on windows.
Internet speed not issue here, i already reported earlier (not to Kimi) but to another big software about the issue and its fixed by simple changes in script.

Review the Windows installation path in install.ps1, starting at the Invoke-WebRequest call that downloads the binary. Check how the suggested Start-BitsTransfer replacement interacts with the existing temporary file and checksum verification. Done means the Windows installer downloads the release binary through the faster path while preserving checksum verification.