chore: import upstream snapshot with attribution

.github/skills/release-note-generation/scripts/diff_prs.ps1

@@ -0,0 +1,100 @@
+<#
+.SYNOPSIS
+    Produce an incremental PR CSV containing rows present in a newer full export but absent from a baseline export.
+
+.DESCRIPTION
+    Compares two previously generated sorted PR CSV files (same schema). Any row whose key column value
+    (defaults to 'Number') does not exist in the baseline file is emitted to a new incremental CSV, preserving
+    the original column order. If no new rows are found, an empty CSV (with headers when determinable) is written.
+
+.PARAMETER BaseCsv
+    Path to the baseline (earlier) PR CSV.
+
+.PARAMETER AllCsv
+    Path to the newer full PR CSV containing superset (or equal set) of rows.
+
+.PARAMETER OutCsv
+    Path to write the incremental CSV containing only new rows.
+
+.PARAMETER Key
+    Column name used as unique identifier (defaults to 'Number'). Must exist in both CSVs.
+
+.EXAMPLE
+    pwsh ./diff_prs.ps1 -BaseCsv sorted_prs_prev.csv -AllCsv sorted_prs.csv -OutCsv sorted_prs_incremental.csv
+
+.NOTES
+    Requires: PowerShell 7+, both CSVs with identical column schemas.
+    Exit code 0 on success (even if zero incremental rows). Throws on missing files.
+#>
+
+[CmdletBinding()] param(
+    [Parameter(Mandatory=$false)][string]$BaseCsv = "./sorted_prs_93_round1.csv",
+    [Parameter(Mandatory=$false)][string]$AllCsv  = "./sorted_prs.csv",
+    [Parameter(Mandatory=$false)][string]$OutCsv  = "./sorted_prs_93_incremental.csv",
+    [Parameter(Mandatory=$false)][string]$Key     = "Number"
+)
+
+Set-StrictMode -Version Latest
+$ErrorActionPreference = 'Stop'
+
+function Write-Info($m) { Write-Host "[info] $m" -ForegroundColor Cyan }
+function Write-Warn($m) { Write-Host "[warn] $m" -ForegroundColor Yellow }
+
+if (-not (Test-Path -LiteralPath $BaseCsv)) { throw "Base CSV not found: $BaseCsv" }
+if (-not (Test-Path -LiteralPath $AllCsv)) { throw "All CSV not found: $AllCsv" }
+
+# Load CSVs
+$baseRows = Import-Csv -LiteralPath $BaseCsv
+$allRows  = Import-Csv -LiteralPath $AllCsv
+
+if (-not $baseRows) { Write-Warn "Base CSV has no rows." }
+if (-not $allRows)  { Write-Warn "All CSV has no rows." }
+
+# Validate key presence
+if ($baseRows -and -not ($baseRows[0].PSObject.Properties.Name -contains $Key)) { throw "Key column '$Key' not found in base CSV." }
+if ($allRows  -and -not ($allRows[0].PSObject.Properties.Name -contains $Key))  { throw "Key column '$Key' not found in all CSV." }
+
+# Build a set of existing keys from base
+$set = New-Object 'System.Collections.Generic.HashSet[string]'
+foreach ($row in $baseRows) {
+    $val = [string]($row.$Key)
+    if ($null -ne $val) { [void]$set.Add($val) }
+}
+
+# Filter rows in AllCsv whose key is not in base (these are the new / incremental rows)
+$incremental = @()
+foreach ($row in $allRows) {
+    $val = [string]($row.$Key)
+    if (-not $set.Contains($val)) { $incremental += $row }
+}
+
+# Preserve column order from the All CSV
+$columns = @()
+if ($allRows.Count -gt 0) {
+    $columns = $allRows[0].PSObject.Properties.Name
+}
+
+try {
+    if ($incremental.Count -gt 0) {
+        if ($columns.Count -gt 0) {
+            $incremental | Select-Object -Property $columns | Export-Csv -LiteralPath $OutCsv -NoTypeInformation -Encoding UTF8
+        } else {
+            $incremental | Export-Csv -LiteralPath $OutCsv -NoTypeInformation -Encoding UTF8
+        }
+    } else {
+        # Write an empty CSV with headers if we know them (facilitates downstream tooling expecting header row)
+        if ($columns.Count -gt 0) {
+            $obj = [PSCustomObject]@{}
+            foreach ($c in $columns) { $obj | Add-Member -NotePropertyName $c -NotePropertyValue $null }
+            $obj | Select-Object -Property $columns | Export-Csv -LiteralPath $OutCsv -NoTypeInformation -Encoding UTF8
+        } else {
+            '' | Out-File -LiteralPath $OutCsv -Encoding UTF8
+        }
+    }
+    Write-Info ("Incremental rows: {0}" -f $incremental.Count)
+    Write-Info ("Output: {0}" -f (Resolve-Path -LiteralPath $OutCsv))
+}
+catch {
+    Write-Host "[error] Failed writing output CSV: $_" -ForegroundColor Red
+    exit 1
+}