fix: use line-by-line Select-String for checksum lookup in install.ps1

Get-Content -Raw returns the file as a single string, so Select-String
treated it as one line and ^ only matched the start of the file.
Reading line by line allows ^ to anchor correctly per line.

Author: codemedic

install.ps1

@@ -53,8 +53,9 @@ if ($currentVer -eq $UvVersion) {
     New-Item -ItemType Directory -Force -Path $Prefix | Out-Null
     $tmp    = [IO.Path]::Combine([IO.Path]::GetTempPath(), [IO.Path]::ChangeExtension([IO.Path]::GetRandomFileName(), ".zip"))
     $tmpDir = "$tmp.dir"
-    $tomlContent  = Get-Content (Join-Path $ScriptDir "distro.toml") -Raw
-    $expectedHash = ($tomlContent | Select-String "^${arch}-pc-windows-msvc\s*=\s*`"([^`"]+)`"").Matches[0].Groups[1].Value.ToUpper()
+    $tomlMatch    = Get-Content (Join-Path $ScriptDir "distro.toml") |
+                        Select-String "^${arch}-pc-windows-msvc\s*=\s*`"([^`"]+)`""
+    $expectedHash = $tomlMatch.Matches[0].Groups[1].Value.ToUpper()
     if (-not $expectedHash) {
         Write-Error "No pinned checksum for ${arch}-pc-windows-msvc in distro.toml"
         exit 1