Add PowerShell script for private npm package installation

This script installs a specified package from a custom npm registry using Azure DevOps PAT for authentication.

Author: hydraxman

deepstudio/private-install.ps1

@@ -0,0 +1,63 @@
+$ErrorActionPreference = "Stop"
+
+$PackageName = if ($env:DEEPSTUDIO_PKG) { $env:DEEPSTUDIO_PKG } else { "deepstudio-server" }
+
+function Require-Npm {
+  if (-not (Get-Command npm -ErrorAction SilentlyContinue)) {
+    Write-Host ""
+    Write-Host "❌ Node.js / npm not found."
+    Write-Host "Please install Node.js first:"
+    Write-Host "https://nodejs.org/en/download"
+    Write-Host ""
+    exit 1
+  }
+}
+
+function Read-Secure([string]$msg) {
+  $secure = Read-Host $msg -AsSecureString
+  $bstr = [Runtime.InteropServices.Marshal]::SecureStringToBSTR($secure)
+  try { [Runtime.InteropServices.Marshal]::PtrToStringBSTR($bstr) }
+  finally { [Runtime.InteropServices.Marshal]::ZeroFreeBSTR($bstr) }
+}
+
+function SetCfg($k, $v) { npm config set --global $k $v | Out-Null }
+function DelCfg($k) { try { npm config delete --global $k | Out-Null } catch {} }
+
+Require-Npm
+
+$registry = Read-Host "Enter npm registry URL (Azure Artifacts)"
+if ([string]::IsNullOrWhiteSpace($registry)) {
+  throw "Registry URL is required."
+}
+
+# normalize registry
+$registry = $registry.TrimEnd("/")
+
+# derive auth prefix
+$uri = [Uri]$registry
+$authPrefix = "//" + $uri.Host + $uri.AbsolutePath + "/"
+
+$pat = Read-Secure "Enter Azure DevOps PAT (Packaging:Read)"
+if ([string]::IsNullOrWhiteSpace($pat)) {
+  throw "PAT is empty."
+}
+
+$patB64 = [Convert]::ToBase64String([Text.Encoding]::UTF8.GetBytes($pat))
+$pat = $null
+
+try {
+  Write-Host "Installing $PackageName@latest"
+
+  SetCfg "registry" "$registry/"
+  SetCfg "${authPrefix}:username" "microsoft"
+  SetCfg "${authPrefix}:_password" $patB64
+  SetCfg "${authPrefix}:email" "npm@example.com"
+
+  npm install -g "$PackageName@latest" --registry "$registry/"
+}
+finally {
+  DelCfg "registry"
+  DelCfg "${authPrefix}:username"
+  DelCfg "${authPrefix}:_password"
+  DelCfg "${authPrefix}:email"
+}