chore: import upstream snapshot with attribution

scripts/refresh-integrity-tree.ps1

@@ -0,0 +1,48 @@
+#!/usr/bin/env pwsh
+<#
+.SYNOPSIS
+    Regenerates IntegrityTree.json and validates it against the current folder contents.
+
+.PARAMETER Path
+    The directory whose IntegrityTree.json should be refreshed and validated.
+
+.PARAMETER FailOnUnexpectedFiles
+    Fail validation if files exist in the directory tree but are not present in
+    IntegrityTree.json.
+#>
+
+[CmdletBinding()]
+param(
+    [Parameter(Mandatory, Position = 0)]
+    [string] $Path,
+
+    [switch] $FailOnUnexpectedFiles
+)
+
+$ErrorActionPreference = 'Stop'
+
+if (-not (Test-Path $Path -PathType Container)) {
+    throw "The directory '$Path' does not exist."
+}
+
+$Path = (Resolve-Path $Path).Path
+$GenerateScriptPath = Join-Path $PSScriptRoot 'generate-integrity-tree.ps1'
+$VerifyScriptPath = Join-Path $PSScriptRoot 'verify-integrity-tree.ps1'
+
+if (-not (Test-Path $GenerateScriptPath -PathType Leaf)) {
+    throw "Integrity tree generator not found at '$GenerateScriptPath'."
+}
+
+if (-not (Test-Path $VerifyScriptPath -PathType Leaf)) {
+    throw "Integrity tree validator not found at '$VerifyScriptPath'."
+}
+
+Write-Host "Refreshing integrity tree in $Path..."
+& $GenerateScriptPath -Path $Path -MinOutput
+
+$ValidationParameters = @{ Path = $Path }
+if ($FailOnUnexpectedFiles) {
+    $ValidationParameters.FailOnUnexpectedFiles = $true
+}
+
+& $VerifyScriptPath @ValidationParameters