chore: windows build script

build.ps1

@@ -0,0 +1,31 @@
+# Hysteria local build script for Windows (PowerShell)
+
+$platforms = @("windows/amd64", "linux/amd64", "darwin/amd64")
+$ldflags = "-s -w"
+
+if (!(Get-Command go -ErrorAction SilentlyContinue)) {
+    Write-Host "Error: go is not installed." -ForegroundColor Red
+    exit 1
+}
+
+if (Test-Path build) {
+    Remove-Item -Recurse -Force build
+}
+New-Item -ItemType Directory -Force -Path build
+
+Write-Host "Starting build..." -ForegroundColor Green
+
+foreach ($platform in $platforms) {
+    $env:GOOS = $platform.Split("/")[0]
+    $env:GOARCH = $platform.Split("/")[1]
+    Write-Host "Building $env:GOOS/$env:GOARCH" -ForegroundColor Green
+    $output = "build/hysteria-$env:GOOS-$env:GOARCH"
+    if ($env:GOOS -eq "windows") {
+        $output = "$output.exe"
+    }
+    go build -o $output -ldflags $ldflags ./cmd/
+}
+
+Write-Host "Build complete." -ForegroundColor Green
+
+Get-ChildItem -Path build | Format-Table -AutoSize