Sample Aggregate-SecureBootData.ps1 script

​​​​​​​<#
.SYNOPSIS
    Aggregates Secure Boot status JSON data from multiple devices into summary reports.

.DESCRIPTION
    Reads collected Secure Boot status JSON files and generates:
    - HTML Dashboard with charts and filtering
    - Summary by ConfidenceLevel
    - Unique device bucket analysis for testing strategy
    
    Supports:
    - Per-machine files: HOSTNAME_latest.json (recommended)
    - Single JSON file
    
    Automatically deduplicates by HostName, keeping latest CollectionTime.
    
    By default, only includes devices with "Action Req" or "High" confidence
    to focus on actionable buckets. Use -IncludeAllConfidenceLevels to override.

.PARAMETER InputPath
    Path to JSON file(s):
    - Folder: Reads all *_latest.json files (or *.json if no _latest files)
    - File: Reads single JSON file

.PARAMETER OutputPath
    Path for generated reports (default: .\SecureBootReports)

.EXAMPLE
    # Aggregate from folder of per-machine files (recommended)
    .\Aggregate-SecureBootData.ps1 -InputPath "\\contoso\SecureBootLogs$"
    # Reads: \\contoso\SecureBootLogs$\*_latest.json

.EXAMPLE
    # Custom output location
    .\Aggregate-SecureBootData.ps1 -InputPath "\\contoso\SecureBootLogs$" -OutputPath "C:\Reports\SecureBoot"

.EXAMPLE
    # Include only Action Req and High confidence (default behavior)
    .\Aggregate-SecureBootData.ps1 -InputPath "\\contoso\SecureBootLogs$"
    # Excludes: Observation, Paused, Not Supported

.EXAMPLE
    # Include all confidence levels (override filter)
    .\Aggregate-SecureBootData.ps1 -InputPath "\\contoso\SecureBootLogs$" -IncludeAllConfidenceLevels

.EXAMPLE
    # Custom confidence level filter
    .\Aggregate-SecureBootData.ps1 -InputPath "\\contoso\SecureBootLogs$" -IncludeConfidenceLevels @("Action Req", "High", "Observation")

.EXAMPLE
    # ENTERPRISE SCALE: Incremental mode - only process changed files (fast subsequent runs)
    .\Aggregate-SecureBootData.ps1 -InputPath "\\contoso\SecureBootLogs$" -IncrementalMode
    # First run: Full load ~2 hours for 500K devices
    # Subsequent runs: Seconds if no changes, minutes for deltas

.EXAMPLE
    # Skip HTML if nothing changed (fastest for monitoring)
    .\Aggregate-SecureBootData.ps1 -InputPath "\\contoso\SecureBootLogs$" -IncrementalMode -SkipReportIfUnchanged
    # If no files changed since last run: ~5 seconds

.EXAMPLE
    # Summary only mode - skip large device tables (1-2 minutes vs 20+ minutes)
    .\Aggregate-SecureBootData.ps1 -InputPath "\\contoso\SecureBootLogs$" -SummaryOnly
    # Generates CSVs but skips HTML dashboard with full device tables

.NOTES
    Pair with Detect-SecureBootCertUpdateStatus.ps1 for enterprise deployment.
    See GPO-DEPLOYMENT-GUIDE.md for full deployment guide.
    
    Default behavior excludes Observation, Paused, and Not Supported devices
    to focus reporting on actionable device buckets only.
#>

param(
    [Parameter(Mandatory = $true)]
    [string]$InputPath,
    
    [Parameter(Mandatory = $false)]
    [string]$OutputPath = ".\SecureBootReports",
    
    [Parameter(Mandatory = $false)]
    [string]$ScanHistoryPath = ".\SecureBootReports\ScanHistory.json",
    
    [Parameter(Mandatory = $false)]
    [string]$RolloutStatePath,  # Path to RolloutState.json to identify InProgress devices
    
    [Parameter(Mandatory = $false)]
    [string]$RolloutSummaryPath,  # Path to SecureBootRolloutSummary.json from Orchestrator (contains projection data)
    
    [Parameter(Mandatory = $false)]
    [string[]]$IncludeConfidenceLevels = @("Action Required", "High Confidence"),  # Only include these confidence levels (default: actionable buckets only)
    
    [Parameter(Mandatory = $false)]
    [switch]$IncludeAllConfidenceLevels,  # Override filter to include all confidence levels
    
    [Parameter(Mandatory = $false)]
    [switch]$SkipHistoryTracking,
    
    [Parameter(Mandatory = $false)]
    [switch]$IncrementalMode,  # Enable delta processing - only load changed files since last run
    
    [Parameter(Mandatory = $false)]
    [string]$CachePath,  # Path to cache directory (default: OutputPath\.cache)
    
    [Parameter(Mandatory = $false)]
    [int]$ParallelThreads = 8,  # Number of parallel threads for file loading (PS7+)
    
    [Parameter(Mandatory = $false)]
    [switch]$ForceFullRefresh,  # Force full reload even in incremental mode
    
    [Parameter(Mandatory = $false)]
    [switch]$SkipReportIfUnchanged,  # Skip HTML/CSV generation if no files changed (just output stats)
    
    [Parameter(Mandatory = $false)]
    [switch]$SummaryOnly,  # Generate summary stats only (no large device tables) - much faster
    
    [Parameter(Mandatory = $false)]
    [switch]$StreamingMode  # Memory-efficient mode: process chunks, write CSVs incrementally, keep only summaries in memory
)

# Auto-elevate to PowerShell 7 if available (6x faster for large datasets)
if ($PSVersionTable.PSVersion.Major -lt 7) {
    $pwshPath = Get-Command pwsh -ErrorAction SilentlyContinue | Select-Object -ExpandProperty Source
    if ($pwshPath) {
        Write-Host "PowerShell $($PSVersionTable.PSVersion) detected - re-launching with PowerShell 7 for faster processing..." -ForegroundColor Yellow
        # Rebuild argument list from bound parameters
        $relaunchArgs = @('-NoProfile', '-ExecutionPolicy', 'Bypass', '-File', $MyInvocation.MyCommand.Path)
        foreach ($key in $PSBoundParameters.Keys) {
            $val = $PSBoundParameters[$key]
            if ($val -is [switch]) {
                if ($val.IsPresent) { $relaunchArgs += "-$key" }
            } elseif ($val -is [array]) {
                $relaunchArgs += "-$key"
                $relaunchArgs += ($val -join ',')
            } else {
                $relaunchArgs += "-$key"
                $relaunchArgs += "$val"
            }
        }
        & $pwshPath @relaunchArgs
        exit $LASTEXITCODE
    }
}

$ErrorActionPreference = "Continue"
$timestamp = Get-Date -Format "yyyyMMdd-HHmmss"
$scanTime = Get-Date -Format "yyyy-MM-dd HH:mm:ss"
$DownloadUrl = "https://aka.ms/getsecureboot"
$DownloadSubPage = "Deployment and Monitoring Samples"

# Note: This script has no dependencies on other scripts.
# For the complete toolset, download from: $DownloadUrl -> $DownloadSubPage

#region Setup
Write-Host "=" * 60 -ForegroundColor Cyan
Write-Host "Secure Boot Data Aggregation" -ForegroundColor Cyan
Write-Host "=" * 60 -ForegroundColor Cyan

# Create output directory
if (-not (Test-Path $OutputPath)) {
    New-Item -ItemType Directory -Path $OutputPath -Force | Out-Null
}

# Load data - supports CSV (legacy) and JSON (native) formats
Write-Host "`nLoading data from: $InputPath" -ForegroundColor Yellow

# Helper function to normalize device object (handle field name differences)
function Normalize-DeviceRecord {
    param($device)
    
    # Handle Hostname vs HostName (JSON uses Hostname, CSV uses HostName)
    if ($device.PSObject.Properties['Hostname'] -and -not $device.PSObject.Properties['HostName']) {
        $device | Add-Member -NotePropertyName 'HostName' -NotePropertyValue $device.Hostname -Force
    }
    
    # Handle Confidence vs ConfidenceLevel (JSON uses Confidence, CSV uses ConfidenceLevel)
    # ConfidenceLevel is the official field name - map Confidence to it
    if ($device.PSObject.Properties['Confidence'] -and -not $device.PSObject.Properties['ConfidenceLevel']) {
        $device | Add-Member -NotePropertyName 'ConfidenceLevel' -NotePropertyValue $device.Confidence -Force
    }
    
    # Track update status via Event1808Count OR UEFICA2023Status="Updated"
    # This allows tracking how many devices in each confidence bucket have been updated
    $event1808 = 0
    if ($device.PSObject.Properties['Event1808Count']) {
        $event1808 = [int]$device.Event1808Count
    }
    $uefiCaUpdated = $false
    if ($device.PSObject.Properties['UEFICA2023Status'] -and $device.UEFICA2023Status -eq "Updated") {
        $uefiCaUpdated = $true
    }
    
    if ($event1808 -gt 0 -or $uefiCaUpdated) {
        # Mark as updated for dashboard/rollout logic - but DON'T override ConfidenceLevel
        $device | Add-Member -NotePropertyName 'IsUpdated' -NotePropertyValue $true -Force
    } else {
        $device | Add-Member -NotePropertyName 'IsUpdated' -NotePropertyValue $false -Force
        
        # ConfidenceLevel classification:
        # - "High Confidence", "Under Observation...", "Temporarily Paused...", "Not Supported..." = use as-is
        # - Everything else (null, empty, "UpdateType:...", "Unknown", "N/A") = falls to Action Required in counters
        # No normalization needed — the streaming counter's else branch handles it
    }
    
    # Handle OEMManufacturerName vs WMI_Manufacturer (JSON uses OEM*, legacy uses WMI_*)
    if ($device.PSObject.Properties['OEMManufacturerName'] -and -not $device.PSObject.Properties['WMI_Manufacturer']) {
        $device | Add-Member -NotePropertyName 'WMI_Manufacturer' -NotePropertyValue $device.OEMManufacturerName -Force
    }
    
    # Handle OEMModelNumber vs WMI_Model
    if ($device.PSObject.Properties['OEMModelNumber'] -and -not $device.PSObject.Properties['WMI_Model']) {
        $device | Add-Member -NotePropertyName 'WMI_Model' -NotePropertyValue $device.OEMModelNumber -Force
    }
    
    # Handle FirmwareVersion vs BIOSDescription
    if ($device.PSObject.Properties['FirmwareVersion'] -and -not $device.PSObject.Properties['BIOSDescription']) {
        $device | Add-Member -NotePropertyName 'BIOSDescription' -NotePropertyValue $device.FirmwareVersion -Force
    }
    
    return $device
}

#region Incremental Processing / Cache Management
# Setup cache paths
if (-not $CachePath) {
    $CachePath = Join-Path $OutputPath ".cache"
}
$manifestPath = Join-Path $CachePath "FileManifest.json"
$deviceCachePath = Join-Path $CachePath "DeviceCache.json"

# Cache management functions
function Get-FileManifest {
    param([string]$Path)
    if (Test-Path $Path) {
        try {
            $json = Get-Content $Path -Raw | ConvertFrom-Json
            # Convert PSObject to hashtable (PS5.1 compatible - PS7 has -AsHashtable)
            $ht = @{}
            $json.PSObject.Properties | ForEach-Object { $ht[$_.Name] = $_.Value }
            return $ht
        } catch {
            return @{}
        }
    }
    return @{}
}

function Save-FileManifest {
    param([hashtable]$Manifest, [string]$Path)
    $dir = Split-Path $Path -Parent
    if (-not (Test-Path $dir)) {
        New-Item -ItemType Directory -Path $dir -Force | Out-Null
    }
    $Manifest | ConvertTo-Json -Depth 3 -Compress | Set-Content $Path -Force
}

function Get-DeviceCache {
    param([string]$Path)
    if (Test-Path $Path) {
        try {
            $cacheData = Get-Content $Path -Raw | ConvertFrom-Json
            Write-Host "   Loaded device cache: $($cacheData.Count) devices" -ForegroundColor DarkGray
            return $cacheData
        } catch {
            Write-Host "   Cache corrupted, will rebuild" -ForegroundColor Yellow
            return @()
        }
    }
    return @()
}

function Save-DeviceCache {
    param($Devices, [string]$Path)
    $dir = Split-Path $Path -Parent
    if (-not (Test-Path $dir)) {
        New-Item -ItemType Directory -Path $dir -Force | Out-Null
    }
    # Convert to array and save
    $deviceArray = @($Devices)
    $deviceArray | ConvertTo-Json -Depth 10 -Compress | Set-Content $Path -Force
    Write-Host "   Saved device cache: $($deviceArray.Count) devices" -ForegroundColor DarkGray
}

function Get-ChangedFiles {
    param(
        [System.IO.FileInfo[]]$AllFiles,
        [hashtable]$Manifest
    )
    
    $changed = [System.Collections.ArrayList]::new()
    $unchanged = [System.Collections.ArrayList]::new()
    $newManifest = @{}
    
    # Build case-insensitive lookup from manifest (normalize to lowercase)
    $manifestLookup = @{}
    foreach ($mk in $Manifest.Keys) {
        $manifestLookup[$mk.ToLowerInvariant()] = $Manifest[$mk]
    }
    
    foreach ($file in $AllFiles) {
        $key = $file.FullName.ToLowerInvariant()  # Normalize path to lowercase
        $lwt = $file.LastWriteTimeUtc.ToString("o")
        $newManifest[$key] = @{
            LastWriteTimeUtc = $lwt
            Size = $file.Length
        }
        
        if ($manifestLookup.ContainsKey($key)) {
            $cached = $manifestLookup[$key]
            if ($cached.LastWriteTimeUtc -eq $lwt -and $cached.Size -eq $file.Length) {
                [void]$unchanged.Add($file)
                continue
            }
        }
        [void]$changed.Add($file)
    }
    
    return @{
        Changed = $changed
        Unchanged = $unchanged
        NewManifest = $newManifest
    }
}

# Ultra-fast parallel file loading using batched processing
function Load-FilesParallel {
    param(
        [System.IO.FileInfo[]]$Files,
        [int]$Threads = 8
    )

    $totalFiles = $Files.Count
    
    # Use batches of ~1000 files each for better memory control
    $batchSize = [math]::Min(1000, [math]::Ceiling($totalFiles / [math]::Max(1, $Threads)))
    $batches = [System.Collections.Generic.List[object]]::new()

    for ($i = 0; $i -lt $totalFiles; $i += $batchSize) {
        $end = [math]::Min($i + $batchSize, $totalFiles)
        $batch = $Files[$i..($end-1)]
        $batches.Add($batch)
    }
    
    Write-Host " ($($batches.Count) batches of ~$batchSize files each)" -NoNewline -ForegroundColor DarkGray
    
    $flatResults = [System.Collections.Generic.List[object]]::new()
    
    # Check if PowerShell 7+ parallel is available
    $canParallel = $PSVersionTable.PSVersion.Major -ge 7
    
    if ($canParallel -and $Threads -gt 1) {
        # PS7+: Process batches in parallel
        $results = $batches | ForEach-Object -ThrottleLimit $Threads -Parallel {
            $batchFiles = $_
            $batchResults = [System.Collections.Generic.List[object]]::new()
            foreach ($file in $batchFiles) {
                try {
                    $content = [System.IO.File]::ReadAllText($file.FullName) | ConvertFrom-Json
                    $batchResults.Add($content)
                } catch { }
            }
            $batchResults.ToArray()
        }
        foreach ($batch in $results) {
            if ($batch) { foreach ($item in $batch) { $flatResults.Add($item) } }
        }
    } else {
        # PS5.1 fallback: Sequential processing (still fast for <10K files)
        foreach ($file in $Files) {
            try {
                $content = [System.IO.File]::ReadAllText($file.FullName) | ConvertFrom-Json
                $flatResults.Add($content)
            } catch { }
        }
    }
    
    return $flatResults.ToArray()
}
#endregion

$allDevices = @()
if (Test-Path $InputPath -PathType Leaf) {
    # Single JSON file
    if ($InputPath -like "*.json") {
        $jsonContent = Get-Content -Path $InputPath -Raw | ConvertFrom-Json
        $allDevices = @($jsonContent) | ForEach-Object { Normalize-DeviceRecord $_ }
        Write-Host "Loaded $($allDevices.Count) records from file"
    } else {
        Write-Error "Only JSON format is supported. File must have .json extension."
        exit 1
    }
} elseif (Test-Path $InputPath -PathType Container) {
    # Folder - JSON only
    $jsonFiles = @(Get-ChildItem -Path $InputPath -Filter "*.json" -Recurse -ErrorAction SilentlyContinue | 
                   Where-Object { $_.Name -notmatch "ScanHistory|RolloutState|RolloutPlan" })
    
    # Prefer *_latest.json files if they exist (per-machine mode)
    $latestJson = $jsonFiles | Where-Object { $_.Name -like "*_latest.json" }
    if ($latestJson.Count -gt 0) { $jsonFiles = $latestJson }
    
    $totalFiles = $jsonFiles.Count
    
    if ($totalFiles -eq 0) {
        Write-Error "No JSON files found in: $InputPath"
        exit 1
    }
    
    Write-Host "Found $totalFiles JSON files" -ForegroundColor Gray
    
    # Helper function to match confidence levels (handles both short and full forms)
    # Defined early so both StreamingMode and normal paths can use it
    function Test-ConfidenceLevel {
        param([string]$Value, [string]$Match)
        if ([string]::IsNullOrEmpty($Value)) { return $false }
        switch ($Match) {
            "HighConfidence"     { return $Value -eq "High Confidence" }
            "UnderObservation"   { return $Value -like "Under Observation*" }
            "ActionRequired"     { return ($Value -like "*Action Required*" -or $Value -eq "Action Required") }
            "TemporarilyPaused"  { return $Value -like "Temporarily Paused*" }
            "NotSupported"       { return ($Value -like "Not Supported*" -or $Value -eq "Not Supported") }
            default              { return $false }
        }
    }
    
    #region STREAMING MODE - Memory-efficient processing for large datasets
    # Always use StreamingMode for memory-efficient processing and new-style dashboard
    if (-not $StreamingMode) {
        Write-Host "Auto-enabling StreamingMode (new-style dashboard)" -ForegroundColor Yellow
        $StreamingMode = $true
        if (-not $IncrementalMode) { $IncrementalMode = $true }
    }
    
    # When -StreamingMode is enabled, process files in chunks keeping only counters in memory.
    # Device-level data is written to JSON files per-chunk for on-demand loading in the dashboard.
    # Memory usage: ~1.5 GB regardless of dataset size (vs 10-20 GB without streaming).
    if ($StreamingMode) {
        Write-Host "STREAMING MODE enabled - memory-efficient processing" -ForegroundColor Green
        $streamSw = [System.Diagnostics.Stopwatch]::StartNew()
        
        # INCREMENTAL CHECK: If no files changed since last run, skip processing entirely
        if ($IncrementalMode -and -not $ForceFullRefresh) {
            $stManifestDir = Join-Path $OutputPath ".cache"
            $stManifestPath = Join-Path $stManifestDir "StreamingManifest.json"
            if (Test-Path $stManifestPath) {
                Write-Host "Checking for changes since last streaming run..." -ForegroundColor Cyan
                $stOldManifest = Get-FileManifest -Path $stManifestPath
                if ($stOldManifest.Count -gt 0) {
                    $stChanged = $false
                    # Quick check: same file count?
                    if ($stOldManifest.Count -eq $totalFiles) {
                        # Check the 100 NEWEST files (sorted by LastWriteTime descending)
                        # If any file changed, it will have the most recent timestamp and appear first
                        $sampleSize = [math]::Min(100, $totalFiles)
                        $sampleFiles = $jsonFiles | Sort-Object LastWriteTimeUtc -Descending | Select-Object -First $sampleSize
                        foreach ($sf in $sampleFiles) {
                            $sfKey = $sf.FullName.ToLowerInvariant()
                            if (-not $stOldManifest.ContainsKey($sfKey)) {
                                $stChanged = $true
                                break
                            }
                            # Compare timestamps - cached may be DateTime or string after JSON roundtrip
                            $cachedLWT = $stOldManifest[$sfKey].LastWriteTimeUtc
                            $fileDT = $sf.LastWriteTimeUtc
                            try {
                                # If cached is already DateTime (ConvertFrom-Json auto-converts), use directly
                                if ($cachedLWT -is [DateTime]) {
                                    $cachedDT = $cachedLWT.ToUniversalTime()
                                } else {
                                    $cachedDT = [DateTimeOffset]::Parse("$cachedLWT").UtcDateTime
                                }
                                if ([math]::Abs(($cachedDT - $fileDT).TotalSeconds) -gt 1) {
                                    $stChanged = $true
                                    break
                                }
                            } catch {
                                $stChanged = $true
                                break
                            }
                        }
                    } else {
                        $stChanged = $true
                    }
                    
                    if (-not $stChanged) {
                        # Check if output files exist
                        $stSummaryExists = Get-ChildItem (Join-Path $OutputPath "SecureBoot_Summary_*.csv") -EA SilentlyContinue | Select-Object -First 1
                        $stDashExists = Get-ChildItem (Join-Path $OutputPath "SecureBoot_Dashboard_*.html") -EA SilentlyContinue | Select-Object -First 1
                        if ($stSummaryExists -and $stDashExists) {
                            Write-Host "   No changes detected ($totalFiles files unchanged) - skipping processing" -ForegroundColor Green
                            Write-Host "   Last dashboard: $($stDashExists.FullName)" -ForegroundColor White
                            $cachedStats = Get-Content $stSummaryExists.FullName | ConvertFrom-Csv
                            Write-Host "   Devices: $($cachedStats.TotalDevices) | Updated: $($cachedStats.Updated) | Errors: $($cachedStats.WithErrors)" -ForegroundColor Gray
                            Write-Host "   Completed in $([math]::Round($streamSw.Elapsed.TotalSeconds, 1))s (no processing needed)" -ForegroundColor Green
                            return $cachedStats
                        }
                    } else {
                        # DELTA PATCH: Find exactly which files changed
                        Write-Host "   Changes detected - identifying changed files..." -ForegroundColor Yellow
                        $changedFiles = [System.Collections.ArrayList]::new()
                        $newFiles = [System.Collections.ArrayList]::new()
                        foreach ($jf in $jsonFiles) {
                            $jfKey = $jf.FullName.ToLowerInvariant()
                            if (-not $stOldManifest.ContainsKey($jfKey)) {
                                [void]$newFiles.Add($jf)
                            } else {
                                $cachedLWT = $stOldManifest[$jfKey].LastWriteTimeUtc
                                $fileDT = $jf.LastWriteTimeUtc
                                try {
                                    $cachedDT = if ($cachedLWT -is [DateTime]) { $cachedLWT.ToUniversalTime() } else { [DateTimeOffset]::Parse("$cachedLWT").UtcDateTime }
                                    if ([math]::Abs(($cachedDT - $fileDT).TotalSeconds) -gt 1) { [void]$changedFiles.Add($jf) }
                                } catch { [void]$changedFiles.Add($jf) }
                            }
                        }
                        $totalChanged = $changedFiles.Count + $newFiles.Count
                        $changePct = [math]::Round(($totalChanged / $totalFiles) * 100, 1)
                        Write-Host "   Changed: $($changedFiles.Count) | New: $($newFiles.Count) | Total: $totalChanged ($changePct%)" -ForegroundColor Yellow
                        
                        if ($totalChanged -gt 0 -and $changePct -lt 10) {
                            # DELTA PATCH MODE: <10% changed, patch existing data
                            Write-Host "   Delta patch mode ($changePct% < 10%) - patching $totalChanged files..." -ForegroundColor Green
                            $dataDir = Join-Path $OutputPath "data"
                            
                            # Load changed/new device records
                            $deltaDevices = @{}
                            $allDeltaFiles = @($changedFiles) + @($newFiles)
                            foreach ($df in $allDeltaFiles) {
                                try {
                                    $devData = Get-Content $df.FullName -Raw | ConvertFrom-Json
                                    $dev = Normalize-DeviceRecord $devData
                                    if ($dev.HostName) { $deltaDevices[$dev.HostName] = $dev }
                                } catch { }
                            }
                            Write-Host "   Loaded $($deltaDevices.Count) changed device records" -ForegroundColor Gray
                            
                            # For each category JSON: remove old entries for changed hostnames, add new entries
                            $categoryFiles = @("errors", "known_issues", "missing_kek", "not_updated",
                                "task_disabled", "temp_failures", "perm_failures", "updated_devices",
                                "action_required", "secureboot_off", "rollout_inprogress")
                            $changedHostnames = [System.Collections.Generic.HashSet[string]]::new([System.StringComparer]::OrdinalIgnoreCase)
                            foreach ($hn in $deltaDevices.Keys) { [void]$changedHostnames.Add($hn) }
                            
                            foreach ($cat in $categoryFiles) {
                                $catPath = Join-Path $dataDir "$cat.json"
                                if (Test-Path $catPath) {
                                    try {
                                        $catData = Get-Content $catPath -Raw | ConvertFrom-Json
                                        # Remove old entries for changed hostnames
                                        $catData = @($catData | Where-Object { -not $changedHostnames.Contains($_.HostName) })
                                        # Re-classify each changed device into categories
                                        # (will be added below after classification)
                                        $catData | ConvertTo-Json -Depth 5 | Set-Content $catPath -Encoding UTF8
                                    } catch { }
                                }
                            }
                            
                            # Classify each changed device and append to the right category files
                            foreach ($dev in $deltaDevices.Values) {
                                $slim = [ordered]@{
                                    HostName = $dev.HostName
                                    WMI_Manufacturer = if ($dev.PSObject.Properties['WMI_Manufacturer']) { $dev.WMI_Manufacturer } else { "" }
                                    WMI_Model = if ($dev.PSObject.Properties['WMI_Model']) { $dev.WMI_Model } else { "" }
                                    BucketId = if ($dev.PSObject.Properties['BucketId']) { $dev.BucketId } else { "" }
                                    ConfidenceLevel = if ($dev.PSObject.Properties['ConfidenceLevel']) { $dev.ConfidenceLevel } else { "" }
                                    IsUpdated = $dev.IsUpdated
                                    UEFICA2023Error = if ($dev.PSObject.Properties['UEFICA2023Error']) { $dev.UEFICA2023Error } else { $null }
                                    SecureBootTaskStatus = if ($dev.PSObject.Properties['SecureBootTaskStatus']) { $dev.SecureBootTaskStatus } else { "" }
                                    KnownIssueId = if ($dev.PSObject.Properties['KnownIssueId']) { $dev.KnownIssueId } else { $null }
                                    SkipReasonKnownIssue = if ($dev.PSObject.Properties['SkipReasonKnownIssue']) { $dev.SkipReasonKnownIssue } else { $null }
                                }
                                
                                $isUpd = $dev.IsUpdated -eq $true
                                $conf = if ($dev.PSObject.Properties['ConfidenceLevel']) { $dev.ConfidenceLevel } else { "" }
                                $hasErr = (-not [string]::IsNullOrEmpty($dev.UEFICA2023Error) -and $dev.UEFICA2023Error -ne "0" -and $dev.UEFICA2023Error -ne "")
                                $tskDis = ($dev.SecureBootTaskEnabled -eq $false -or $dev.SecureBootTaskStatus -eq 'Disabled' -or $dev.SecureBootTaskStatus -eq 'NotFound')
                                $tskNF = ($dev.SecureBootTaskStatus -eq 'NotFound')
                                $sbOn = ($dev.SecureBootEnabled -ne $false -and "$($dev.SecureBootEnabled)" -ne "False")
                                $e1801 = if ($dev.PSObject.Properties['Event1801Count']) { [int]$dev.Event1801Count } else { 0 }
                                $e1808 = if ($dev.PSObject.Properties['Event1808Count']) { [int]$dev.Event1808Count } else { 0 }
                                $e1803 = if ($dev.PSObject.Properties['Event1803Count']) { [int]$dev.Event1803Count } else { 0 }
                                $mKEK = ($e1803 -gt 0 -or $dev.MissingKEK -eq $true)
                                $hKI = ((-not [string]::IsNullOrEmpty($dev.SkipReasonKnownIssue)) -or (-not [string]::IsNullOrEmpty($dev.KnownIssueId)))
                                $rStat = if ($dev.PSObject.Properties['RolloutStatus']) { $dev.RolloutStatus } else { "" }
                                
                                # Append to matching category files
                                $targets = @()
                                if ($isUpd) { $targets += "updated_devices" }
                                if ($hasErr) { $targets += "errors" }
                                if ($hKI) { $targets += "known_issues" }
                                if ($mKEK) { $targets += "missing_kek" }
                                if (-not $isUpd -and $sbOn) { $targets += "not_updated" }
                                if ($tskDis) { $targets += "task_disabled" }
                                if (-not $isUpd -and ($tskDis -or (Test-ConfidenceLevel $conf 'TemporarilyPaused'))) { $targets += "temp_failures" }
                                if (-not $isUpd -and ((Test-ConfidenceLevel $conf 'NotSupported') -or ($tskNF -and $hasErr))) { $targets += "perm_failures" }
                                if (-not $isUpd -and (Test-ConfidenceLevel $conf 'ActionRequired')) { $targets += "action_required" }
                                if (-not $sbOn) { $targets += "secureboot_off" }
                                if ($e1801 -gt 0 -and $e1808 -eq 0 -and -not $hasErr -and $rStat -eq "InProgress") { $targets += "rollout_inprogress" }
                                
                                foreach ($tgt in $targets) {
                                    $tgtPath = Join-Path $dataDir "$tgt.json"
                                    if (Test-Path $tgtPath) {
                                        $existing = Get-Content $tgtPath -Raw | ConvertFrom-Json
                                        $existing = @($existing) + @([PSCustomObject]$slim)
                                        $existing | ConvertTo-Json -Depth 5 | Set-Content $tgtPath -Encoding UTF8
                                    }
                                }
                            }
                            
                            # Regenerate CSVs from patched JSONs
                            Write-Host "   Regenerating CSVs from patched data..." -ForegroundColor Gray
                            $newTimestamp = Get-Date -Format "yyyyMMdd-HHmmss"
                            foreach ($cat in $categoryFiles) {
                                $catJsonPath = Join-Path $dataDir "$cat.json"
                                $catCsvPath = Join-Path $OutputPath "SecureBoot_${cat}_$newTimestamp.csv"
                                if (Test-Path $catJsonPath) {
                                    try {
                                        $catJsonData = Get-Content $catJsonPath -Raw | ConvertFrom-Json
                                        if ($catJsonData.Count -gt 0) {
                                            $catJsonData | Export-Csv -Path $catCsvPath -NoTypeInformation -Encoding UTF8
                                        }
                                    } catch { }
                                }
                            }
                            
                            # Recount stats from the patched JSON files
                            Write-Host "   Recalculating summary from patched data..." -ForegroundColor Gray
                            $patchedStats = [ordered]@{ ReportGeneratedAt = (Get-Date).ToString("yyyy-MM-dd HH:mm:ss") }
                            $pTotal = 0; $pUpdated = 0; $pErrors = 0; $pKI = 0; $pKEK = 0
                            $pTaskDis = 0; $pTempFail = 0; $pPermFail = 0; $pActionReq = 0; $pSBOff = 0; $pRIP = 0
                            foreach ($cat in $categoryFiles) {
                                $catPath = Join-Path $dataDir "$cat.json"
                                $cnt = 0
                                if (Test-Path $catPath) { try { $cnt = (Get-Content $catPath -Raw | ConvertFrom-Json).Count } catch { } }
                                switch ($cat) {
                                    "updated_devices" { $pUpdated = $cnt }
                                    "errors" { $pErrors = $cnt }
                                    "known_issues" { $pKI = $cnt }
                                    "missing_kek" { $pKEK = $cnt }
                                    "not_updated" { } # computed
                                    "task_disabled" { $pTaskDis = $cnt }
                                    "temp_failures" { $pTempFail = $cnt }
                                    "perm_failures" { $pPermFail = $cnt }
                                    "action_required" { $pActionReq = $cnt }
                                    "secureboot_off" { $pSBOff = $cnt }
                                    "rollout_inprogress" { $pRIP = $cnt }
                                }
                            }
                            $pNotUpdated = (Get-Content (Join-Path $dataDir "not_updated.json") -Raw | ConvertFrom-Json).Count
                            $pTotal = $pUpdated + $pNotUpdated + $pSBOff
                            
                            Write-Host "   Delta patch complete: $totalChanged devices updated" -ForegroundColor Green
                            Write-Host "   Total: $pTotal | Updated: $pUpdated | NotUpdated: $pNotUpdated | Errors: $pErrors" -ForegroundColor White
                            
                            # Update manifest
                            $stManifestDir = Join-Path $OutputPath ".cache"
                            $stNewManifest = @{}
                            foreach ($jf in $jsonFiles) {
                                $stNewManifest[$jf.FullName.ToLowerInvariant()] = @{
                                    LastWriteTimeUtc = $jf.LastWriteTimeUtc.ToString("o"); Size = $jf.Length
                                }
                            }
                            Save-FileManifest -Manifest $stNewManifest -Path $stManifestPath
                            
                            Write-Host "   Completed in $([math]::Round($streamSw.Elapsed.TotalSeconds, 1))s (delta patch - $totalChanged devices)" -ForegroundColor Green
                            
                            # Fall through to full streaming reprocess to regenerate HTML dashboard
                            # The data files are already patched, so this ensures dashboard stays current
                            Write-Host "   Regenerating dashboard from patched data..." -ForegroundColor Yellow
                        } else {
                            Write-Host "   $changePct% files changed (>= 10%) - full streaming reprocess required" -ForegroundColor Yellow
                        }
                    }
                }
            }
        }
        
        # Create data subdirectory for on-demand device JSON files
        $dataDir = Join-Path $OutputPath "data"
        if (-not (Test-Path $dataDir)) { New-Item -ItemType Directory -Path $dataDir -Force | Out-Null }
        
        # Deduplication via HashSet (O(1) per lookup, ~50MB for 600K hostnames)
        $seenHostnames = [System.Collections.Generic.HashSet[string]]::new([System.StringComparer]::OrdinalIgnoreCase)
        
        # Lightweight summary counters (replaces $allDevices + $uniqueDevices in memory)
        $c = @{
            Total = 0; SBEnabled = 0; SBOff = 0
            Updated = 0; HighConf = 0; UnderObs = 0; ActionReq = 0; TempPaused = 0; NotSupported = 0; NoConfData = 0
            TaskDisabled = 0; TaskNotFound = 0; TaskDisabledNotUpdated = 0
            WithErrors = 0; InProgress = 0; NotYetInitiated = 0; RolloutInProgress = 0
            WithKnownIssues = 0; WithMissingKEK = 0; TempFailures = 0; PermFailures = 0; NeedsReboot = 0
            UpdatePending = 0
        }
        
        # Bucket tracking for AtRisk/SafeList (lightweight sets)
        $stFailedBuckets = [System.Collections.Generic.HashSet[string]]::new()
        $stSuccessBuckets = [System.Collections.Generic.HashSet[string]]::new()
        $stAllBuckets = @{}
        $stMfrCounts = @{}
        $stErrorCodeCounts = @{}; $stErrorCodeSamples = @{}
        $stKnownIssueCounts = @{}
        
        # Batch-mode device data files: accumulate per-chunk, flush at chunk boundaries
        $stDeviceFiles = @("errors", "known_issues", "missing_kek", "not_updated", 
            "task_disabled", "temp_failures", "perm_failures", "updated_devices", "action_required",
            "secureboot_off", "rollout_inprogress", "under_observation", "needs_reboot", "update_pending")
        $stDeviceFilePaths = @{}; $stDeviceFileCounts = @{}
        foreach ($dfName in $stDeviceFiles) {
            $dfPath = Join-Path $dataDir "$dfName.json"
            [System.IO.File]::WriteAllText($dfPath, "[`n", [System.Text.Encoding]::UTF8)
            $stDeviceFilePaths[$dfName] = $dfPath; $stDeviceFileCounts[$dfName] = 0
        }
        
        # Slim device record for JSON output (only essential fields, ~200 bytes vs ~2KB full)
        function Get-SlimDevice {
            param($Dev)
            return [ordered]@{
                HostName = $Dev.HostName
                WMI_Manufacturer = if ($Dev.PSObject.Properties['WMI_Manufacturer']) { $Dev.WMI_Manufacturer } else { "" }
                WMI_Model = if ($Dev.PSObject.Properties['WMI_Model']) { $Dev.WMI_Model } else { "" }
                BucketId = if ($Dev.PSObject.Properties['BucketId']) { $Dev.BucketId } else { "" }
                ConfidenceLevel = if ($Dev.PSObject.Properties['ConfidenceLevel']) { $Dev.ConfidenceLevel } else { "" }
                IsUpdated = $Dev.IsUpdated
                UEFICA2023Error = if ($Dev.PSObject.Properties['UEFICA2023Error']) { $Dev.UEFICA2023Error } else { $null }
                SecureBootTaskStatus = if ($Dev.PSObject.Properties['SecureBootTaskStatus']) { $Dev.SecureBootTaskStatus } else { "" }
                KnownIssueId = if ($Dev.PSObject.Properties['KnownIssueId']) { $Dev.KnownIssueId } else { $null }
                SkipReasonKnownIssue = if ($Dev.PSObject.Properties['SkipReasonKnownIssue']) { $Dev.SkipReasonKnownIssue } else { $null }
                UEFICA2023Status = if ($Dev.PSObject.Properties['UEFICA2023Status']) { $Dev.UEFICA2023Status } else { $null }
                AvailableUpdatesPolicy = if ($Dev.PSObject.Properties['AvailableUpdatesPolicy']) { $Dev.AvailableUpdatesPolicy } else { $null }
                WinCSKeyApplied = if ($Dev.PSObject.Properties['WinCSKeyApplied']) { $Dev.WinCSKeyApplied } else { $null }
            }
        }
        
        # Flush batch to JSON file (append mode)
        function Flush-DeviceBatch {
            param([string]$StreamName, [System.Collections.Generic.List[object]]$Batch)
            if ($Batch.Count -eq 0) { return }
            $fPath = $stDeviceFilePaths[$StreamName]
            $fSb = [System.Text.StringBuilder]::new()
            foreach ($fDev in $Batch) {
                if ($stDeviceFileCounts[$StreamName] -gt 0) { [void]$fSb.Append(",`n") }
                [void]$fSb.Append(($fDev | ConvertTo-Json -Compress))
                $stDeviceFileCounts[$StreamName]++
            }
            [System.IO.File]::AppendAllText($fPath, $fSb.ToString(), [System.Text.Encoding]::UTF8)
        }
        
        # MAIN STREAMING LOOP
        $stChunkSize = if ($totalFiles -le 10000) { $totalFiles } else { 10000 }
        $stTotalChunks = [math]::Ceiling($totalFiles / $stChunkSize)
        $stPeakMemMB = 0
        if ($stTotalChunks -gt 1) {
            Write-Host "Processing $totalFiles files in $stTotalChunks chunks of $stChunkSize (streaming, $ParallelThreads threads):" -ForegroundColor Cyan
        } else {
            Write-Host "Processing $totalFiles files (streaming, $ParallelThreads threads):" -ForegroundColor Cyan
        }
        
        for ($ci = 0; $ci -lt $stTotalChunks; $ci++) {
            $cStart = $ci * $stChunkSize
            $cEnd = [math]::Min($cStart + $stChunkSize, $totalFiles) - 1
            $cFiles = $jsonFiles[$cStart..$cEnd]
            
            if ($stTotalChunks -gt 1) {
                Write-Host "   Chunk $($ci + 1)/$stTotalChunks ($($cFiles.Count) files): " -NoNewline -ForegroundColor Gray
            } else {
                Write-Host "   Loading $($cFiles.Count) files: " -NoNewline -ForegroundColor Gray
            }
            $cSw = [System.Diagnostics.Stopwatch]::StartNew()
            
            $rawDevices = Load-FilesParallel -Files $cFiles -Threads $ParallelThreads
            
            # Per-chunk batch lists
            $cBatches = @{}
            foreach ($df in $stDeviceFiles) { $cBatches[$df] = [System.Collections.Generic.List[object]]::new() }
            
            $cNew = 0; $cDupe = 0
            foreach ($raw in $rawDevices) {
                if (-not $raw) { continue }
                $device = Normalize-DeviceRecord $raw
                $hostname = $device.HostName
                if (-not $hostname) { continue }
                
                if ($seenHostnames.Contains($hostname)) { $cDupe++; continue }
                [void]$seenHostnames.Add($hostname)
                $cNew++; $c.Total++
                
                $sbOn = ($device.SecureBootEnabled -ne $false -and "$($device.SecureBootEnabled)" -ne "False")
                if ($sbOn) { $c.SBEnabled++ } else { $c.SBOff++; $cBatches["secureboot_off"].Add((Get-SlimDevice $device)) }
                
                $isUpd = $device.IsUpdated -eq $true
                $conf = if ($device.PSObject.Properties['ConfidenceLevel'] -and $device.ConfidenceLevel) { "$($device.ConfidenceLevel)" } else { "" }
                $hasErr = (-not [string]::IsNullOrEmpty($device.UEFICA2023Error) -and "$($device.UEFICA2023Error)" -ne "0" -and "$($device.UEFICA2023Error)" -ne "")
                $tskDis = ($device.SecureBootTaskEnabled -eq $false -or "$($device.SecureBootTaskStatus)" -eq 'Disabled' -or "$($device.SecureBootTaskStatus)" -eq 'NotFound')
                $tskNF = ("$($device.SecureBootTaskStatus)" -eq 'NotFound')
                $bid = if ($device.PSObject.Properties['BucketId'] -and $device.BucketId) { "$($device.BucketId)" } else { "" }
                $e1808 = if ($device.PSObject.Properties['Event1808Count']) { [int]$device.Event1808Count } else { 0 }
                $e1801 = if ($device.PSObject.Properties['Event1801Count']) { [int]$device.Event1801Count } else { 0 }
                $e1803 = if ($device.PSObject.Properties['Event1803Count']) { [int]$device.Event1803Count } else { 0 }
                $mKEK = ($e1803 -gt 0 -or $device.MissingKEK -eq $true -or "$($device.MissingKEK)" -eq "True")
                $hKI = ((-not [string]::IsNullOrEmpty($device.SkipReasonKnownIssue)) -or (-not [string]::IsNullOrEmpty($device.KnownIssueId)))
                $rStat = if ($device.PSObject.Properties['RolloutStatus']) { $device.RolloutStatus } else { "" }
                $mfr = if ($device.PSObject.Properties['WMI_Manufacturer'] -and -not [string]::IsNullOrEmpty($device.WMI_Manufacturer)) { $device.WMI_Manufacturer } else { "Unknown" }
                $bid = if (-not [string]::IsNullOrEmpty($bid)) { $bid } else { "" }
                
                # Pre-compute Update Pending flag (policy/WinCS applied, status not yet Updated, SB ON, task not disabled)
                $uefiStatus = if ($device.PSObject.Properties['UEFICA2023Status']) { "$($device.UEFICA2023Status)" } else { "" }
                $hasPolicy = ($device.PSObject.Properties['AvailableUpdatesPolicy'] -and $null -ne $device.AvailableUpdatesPolicy -and "$($device.AvailableUpdatesPolicy)" -ne '')
                $hasWinCS = ($device.PSObject.Properties['WinCSKeyApplied'] -and $device.WinCSKeyApplied -eq $true)
                $statusPending = ([string]::IsNullOrEmpty($uefiStatus) -or $uefiStatus -eq 'NotStarted' -or $uefiStatus -eq 'InProgress')
                $isUpdatePending = (($hasPolicy -or $hasWinCS) -and $statusPending -and -not $isUpd -and $sbOn -and -not $tskDis)
                
                if ($isUpd) {
                    $c.Updated++; [void]$stSuccessBuckets.Add($bid); $cBatches["updated_devices"].Add((Get-SlimDevice $device))
                    # Track Updated devices that need reboot (UEFICA2023Status=Updated but Event1808=0)
                    if ($e1808 -eq 0) { $c.NeedsReboot++; $cBatches["needs_reboot"].Add((Get-SlimDevice $device)) }
                }
                elseif (-not $sbOn) { 
                    # SecureBoot OFF — out of scope, don't classify by confidence
                }
                else {
                    if ($isUpdatePending) { } # Counted separately in Update Pending — mutually exclusive for pie chart
                    elseif (Test-ConfidenceLevel $conf "HighConfidence") { $c.HighConf++ }
                    elseif (Test-ConfidenceLevel $conf "UnderObservation") { $c.UnderObs++ }
                    elseif (Test-ConfidenceLevel $conf "TemporarilyPaused") { $c.TempPaused++ }
                    elseif (Test-ConfidenceLevel $conf "NotSupported") { $c.NotSupported++ }
                    else { $c.ActionReq++ }
                    if ([string]::IsNullOrEmpty($conf)) { $c.NoConfData++ }
                }
                
                if ($tskDis) { $c.TaskDisabled++; $cBatches["task_disabled"].Add((Get-SlimDevice $device)) }
                if ($tskNF) { $c.TaskNotFound++ }
                if (-not $isUpd -and $tskDis) { $c.TaskDisabledNotUpdated++ }
                
                if ($hasErr) {
                    $c.WithErrors++; [void]$stFailedBuckets.Add($bid); $cBatches["errors"].Add((Get-SlimDevice $device))
                    $ec = $device.UEFICA2023Error
                    if (-not $stErrorCodeCounts.ContainsKey($ec)) { $stErrorCodeCounts[$ec] = 0; $stErrorCodeSamples[$ec] = @() }
                    $stErrorCodeCounts[$ec]++
                    if ($stErrorCodeSamples[$ec].Count -lt 5) { $stErrorCodeSamples[$ec] += $hostname }
                }
                if ($hKI) {
                    $c.WithKnownIssues++; $cBatches["known_issues"].Add((Get-SlimDevice $device))
                    $ki = if (-not [string]::IsNullOrEmpty($device.SkipReasonKnownIssue)) { $device.SkipReasonKnownIssue } else { $device.KnownIssueId }
                    if (-not $stKnownIssueCounts.ContainsKey($ki)) { $stKnownIssueCounts[$ki] = 0 }; $stKnownIssueCounts[$ki]++
                }
                if ($mKEK) { $c.WithMissingKEK++; $cBatches["missing_kek"].Add((Get-SlimDevice $device)) }
                if (-not $isUpd -and ($tskDis -or (Test-ConfidenceLevel $conf 'TemporarilyPaused'))) { $c.TempFailures++; $cBatches["temp_failures"].Add((Get-SlimDevice $device)) }
                if (-not $isUpd -and ((Test-ConfidenceLevel $conf 'NotSupported') -or ($tskNF -and $hasErr))) { $c.PermFailures++; $cBatches["perm_failures"].Add((Get-SlimDevice $device)) }
                if ($e1801 -gt 0 -and $e1808 -eq 0 -and -not $hasErr -and $rStat -eq "InProgress") { $c.RolloutInProgress++; $cBatches["rollout_inprogress"].Add((Get-SlimDevice $device)) }
                if ($e1801 -gt 0 -and $e1808 -eq 0 -and -not $hasErr -and $rStat -ne "InProgress") { $c.NotYetInitiated++ }
                if ($rStat -eq "InProgress" -and $e1808 -eq 0) { $c.InProgress++ }
                # Update Pending: policy or WinCS applied, status pending, SB ON, task not disabled
                if ($isUpdatePending) {
                    $c.UpdatePending++; $cBatches["update_pending"].Add((Get-SlimDevice $device))
                }
                if (-not $isUpd -and $sbOn) { $cBatches["not_updated"].Add((Get-SlimDevice $device)) }
                # Under Observation devices (separate from Action Required)
                if (-not $isUpd -and (Test-ConfidenceLevel $conf 'UnderObservation')) { $cBatches["under_observation"].Add((Get-SlimDevice $device)) }
                # Action Required: not-updated, SB ON, not matching other confidence categories, not Update Pending
                if (-not $isUpd -and $sbOn -and -not $isUpdatePending -and -not (Test-ConfidenceLevel $conf 'HighConfidence') -and -not (Test-ConfidenceLevel $conf 'UnderObservation') -and -not (Test-ConfidenceLevel $conf 'TemporarilyPaused') -and -not (Test-ConfidenceLevel $conf 'NotSupported')) {
                    $cBatches["action_required"].Add((Get-SlimDevice $device))
                }
                
                if (-not $stMfrCounts.ContainsKey($mfr)) { $stMfrCounts[$mfr] = @{ Total=0; Updated=0; UpdatePending=0; HighConf=0; UnderObs=0; ActionReq=0; TempPaused=0; NotSupported=0; SBOff=0; WithErrors=0 } }
                $stMfrCounts[$mfr].Total++
                if ($isUpd) { $stMfrCounts[$mfr].Updated++ }
                elseif (-not $sbOn) { $stMfrCounts[$mfr].SBOff++ }
                elseif ($isUpdatePending) { $stMfrCounts[$mfr].UpdatePending++ }
                elseif (Test-ConfidenceLevel $conf "HighConfidence") { $stMfrCounts[$mfr].HighConf++ }
                elseif (Test-ConfidenceLevel $conf "UnderObservation") { $stMfrCounts[$mfr].UnderObs++ }
                elseif (Test-ConfidenceLevel $conf "TemporarilyPaused") { $stMfrCounts[$mfr].TempPaused++ }
                elseif (Test-ConfidenceLevel $conf "NotSupported") { $stMfrCounts[$mfr].NotSupported++ }
                else { $stMfrCounts[$mfr].ActionReq++ }
                if ($hasErr) { $stMfrCounts[$mfr].WithErrors++ }
                
                # Track all devices by bucket (including empty BucketId)
                $bucketKey = if ($bid -and $bid -ne "") { $bid } else { "(empty)" }
                if (-not $stAllBuckets.ContainsKey($bucketKey)) {
                    $stAllBuckets[$bucketKey] = @{ Count=0; Updated=0; Manufacturer=$mfr; Model=""; BIOS="" }
                    if ($device.PSObject.Properties['WMI_Model']) { $stAllBuckets[$bucketKey].Model = $device.WMI_Model }
                    if ($device.PSObject.Properties['BIOSDescription']) { $stAllBuckets[$bucketKey].BIOS = $device.BIOSDescription }
                }
                $stAllBuckets[$bucketKey].Count++
                if ($isUpd) { $stAllBuckets[$bucketKey].Updated++ }
            }
            
            # Flush batches to disk
            foreach ($df in $stDeviceFiles) { Flush-DeviceBatch -StreamName $df -Batch $cBatches[$df] }
            $rawDevices = $null; $cBatches = $null; [System.GC]::Collect()
            
            $cSw.Stop()
            $cTime = [Math]::Round($cSw.Elapsed.TotalSeconds, 1)
            $cRem = $stTotalChunks - $ci - 1
            $cEta = if ($cRem -gt 0) { " | ETA: ~$([Math]::Round($cRem * $cSw.Elapsed.TotalSeconds / 60, 1)) min" } else { "" }
            $cMem = [math]::Round([System.GC]::GetTotalMemory($false) / 1MB, 0)
            if ($cMem -gt $stPeakMemMB) { $stPeakMemMB = $cMem }
            Write-Host " +$cNew new, $cDupe dupes, ${cTime}s | Mem: ${cMem}MB$cEta" -ForegroundColor Green
        }
        
        # Finalize JSON arrays
        foreach ($dfName in $stDeviceFiles) {
            [System.IO.File]::AppendAllText($stDeviceFilePaths[$dfName], "`n]", [System.Text.Encoding]::UTF8)
            Write-Host "   $dfName.json: $($stDeviceFileCounts[$dfName]) devices" -ForegroundColor DarkGray
        }
        
        # Compute derived stats
        $stAtRisk = 0; $stSafeList = 0
        foreach ($bid in $stAllBuckets.Keys) {
            $b = $stAllBuckets[$bid]; $nu = $b.Count - $b.Updated
            if ($stFailedBuckets.Contains($bid)) { $stAtRisk += $nu }
            elseif ($stSuccessBuckets.Contains($bid)) { $stSafeList += $nu }
        }
        $stAtRisk = [math]::Max(0, $stAtRisk - $c.WithErrors)
        # NotUptodate = count from not_updated batch (devices with SB ON and not updated)
        $stNotUptodate = $stDeviceFileCounts["not_updated"]
        
        $stats = [ordered]@{
            ReportGeneratedAt = (Get-Date).ToString("yyyy-MM-dd HH:mm:ss")
            TotalDevices = $c.Total; SecureBootEnabled = $c.SBEnabled; SecureBootOFF = $c.SBOff
            Updated = $c.Updated; HighConfidence = $c.HighConf; UnderObservation = $c.UnderObs
            ActionRequired = $c.ActionReq; TemporarilyPaused = $c.TempPaused; NotSupported = $c.NotSupported
            NoConfidenceData = $c.NoConfData; TaskDisabled = $c.TaskDisabled; TaskNotFound = $c.TaskNotFound
            TaskDisabledNotUpdated = $c.TaskDisabledNotUpdated
            CertificatesUpdated = $c.Updated; NotUptodate = $stNotUptodate; FullyUpdated = $c.Updated
            UpdatesPending = $stNotUptodate; UpdatesComplete = $c.Updated
            WithErrors = $c.WithErrors; InProgress = $c.InProgress; NotYetInitiated = $c.NotYetInitiated
            RolloutInProgress = $c.RolloutInProgress; WithKnownIssues = $c.WithKnownIssues
            WithMissingKEK = $c.WithMissingKEK; TemporaryFailures = $c.TempFailures; PermanentFailures = $c.PermFailures
            NeedsReboot = $c.NeedsReboot; UpdatePending = $c.UpdatePending
            AtRiskDevices = $stAtRisk; SafeListDevices = $stSafeList
            PercentWithErrors = if ($c.Total -gt 0) { [math]::Round(($c.WithErrors/$c.Total)*100,2) } else { 0 }
            PercentAtRisk = if ($c.Total -gt 0) { [math]::Round(($stAtRisk/$c.Total)*100,2) } else { 0 }
            PercentSafeList = if ($c.Total -gt 0) { [math]::Round(($stSafeList/$c.Total)*100,2) } else { 0 }
            PercentHighConfidence = if ($c.Total -gt 0) { [math]::Round(($c.HighConf/$c.Total)*100,1) } else { 0 }
            PercentCertUpdated = if ($c.Total -gt 0) { [math]::Round(($c.Updated/$c.Total)*100,1) } else { 0 }
            PercentActionRequired = if ($c.Total -gt 0) { [math]::Round(($c.ActionReq/$c.Total)*100,1) } else { 0 }
            PercentNotUptodate = if ($c.Total -gt 0) { [math]::Round($stNotUptodate/$c.Total*100,1) } else { 0 }
            PercentFullyUpdated = if ($c.Total -gt 0) { [math]::Round(($c.Updated/$c.Total)*100,1) } else { 0 }
            UniqueBuckets = $stAllBuckets.Count; PeakMemoryMB = $stPeakMemMB; ProcessingMode = "Streaming"
        }
        
        # Write CSVs
        [PSCustomObject]$stats | Export-Csv -Path (Join-Path $OutputPath "SecureBoot_Summary_$timestamp.csv") -NoTypeInformation -Encoding UTF8
        $stMfrCounts.GetEnumerator() | Sort-Object { $_.Value.Total } -Descending | ForEach-Object {
            [PSCustomObject]@{ Manufacturer=$_.Key; Count=$_.Value.Total; Updated=$_.Value.Updated; HighConfidence=$_.Value.HighConf; ActionRequired=$_.Value.ActionReq }
        } | Export-Csv -Path (Join-Path $OutputPath "SecureBoot_ByManufacturer_$timestamp.csv") -NoTypeInformation -Encoding UTF8
        $stErrorCodeCounts.GetEnumerator() | Sort-Object Value -Descending | ForEach-Object {
            [PSCustomObject]@{ ErrorCode=$_.Key; Count=$_.Value; SampleDevices=($stErrorCodeSamples[$_.Key] -join ", ") }
        } | Export-Csv -Path (Join-Path $OutputPath "SecureBoot_ErrorCodes_$timestamp.csv") -NoTypeInformation -Encoding UTF8
        $stAllBuckets.GetEnumerator() | Sort-Object { $_.Value.Count } -Descending | ForEach-Object {
            [PSCustomObject]@{ BucketId=$_.Key; Count=$_.Value.Count; Updated=$_.Value.Updated; NotUpdated=$_.Value.Count-$_.Value.Updated; Manufacturer=$_.Value.Manufacturer }
        } | Export-Csv -Path (Join-Path $OutputPath "SecureBoot_UniqueBuckets_$timestamp.csv") -NoTypeInformation -Encoding UTF8
        
        # Generate orchestrator-compatible CSVs (expected filenames for Start-SecureBootRolloutOrchestrator.ps1)
        $notUpdatedJsonPath = Join-Path $dataDir "not_updated.json"
        if (Test-Path $notUpdatedJsonPath) {
            try {
                $nuData = Get-Content $notUpdatedJsonPath -Raw | ConvertFrom-Json
                if ($nuData.Count -gt 0) {
                    # NotUptodate CSV - orchestrator searches for *NotUptodate*.csv
                    $nuData | Export-Csv -Path (Join-Path $OutputPath "SecureBoot_NotUptodate_$timestamp.csv") -NoTypeInformation -Encoding UTF8
                    Write-Host "   Orchestrator CSV: SecureBoot_NotUptodate_$timestamp.csv ($($nuData.Count) devices)" -ForegroundColor Gray
                }
            } catch { }
        }
        
        # Write JSON data for dashboard
        $stats | ConvertTo-Json -Depth 3 | Set-Content (Join-Path $dataDir "summary.json") -Encoding UTF8
        
        # HISTORICAL TRACKING: Save data point for trend chart
        # Use a stable cache location so trend data persists across timestamped aggregation folders.
        # If OutputPath looks like "...\Aggregation_yyyyMMdd_HHmmss", cache goes in the parent folder.
        # Otherwise, cache goes inside OutputPath itself.
        $parentDir = Split-Path $OutputPath -Parent
        $leafName = Split-Path $OutputPath -Leaf
        if ($leafName -match '^Aggregation_\d{8}' -or $leafName -eq 'Aggregation_Current') {
            # Orchestrator-created timestamped folder — use parent for stable cache
            $historyPath = Join-Path $parentDir ".cache\trend_history.json"
        } else {
            $historyPath = Join-Path $OutputPath ".cache\trend_history.json"
        }
        $historyDir = Split-Path $historyPath -Parent
        if (-not (Test-Path $historyDir)) { New-Item -ItemType Directory -Path $historyDir -Force | Out-Null }
        $historyData = @()
        if (Test-Path $historyPath) {
            try { $historyData = @(Get-Content $historyPath -Raw | ConvertFrom-Json) } catch { $historyData = @() }
        }
        # Also check inside OutputPath\.cache\ (legacy location from older versions)
        # Merge any data points not already in the primary history
        if ($leafName -eq 'Aggregation_Current' -or $leafName -match '^Aggregation_\d{8}') {
            $innerHistoryPath = Join-Path $OutputPath ".cache\trend_history.json"
            if ((Test-Path $innerHistoryPath) -and $innerHistoryPath -ne $historyPath) {
                try {
                    $innerData = @(Get-Content $innerHistoryPath -Raw | ConvertFrom-Json)
                    $existingDates = @($historyData | ForEach-Object { $_.Date })
                    foreach ($entry in $innerData) {
                        if ($entry.Date -and $entry.Date -notin $existingDates) {
                            $historyData += $entry
                        }
                    }
                    if ($innerData.Count -gt 0) {
                        Write-Host "   Merged $($innerData.Count) data points from inner cache" -ForegroundColor DarkGray
                    }
                } catch { }
            }
        }

        # BOOTSTRAP: If trend history is empty/sparse, reconstruct from historical data
        if ($historyData.Count -lt 2 -and ($leafName -match '^Aggregation_\d{8}' -or $leafName -eq 'Aggregation_Current')) {
            Write-Host "   Bootstrapping trend history from historical data..." -ForegroundColor Yellow
            $dailyData = @{}
            
            # Source 1: Summary CSVs inside current folder (Aggregation_Current keeps all Summary CSVs)
            $localSummaries = Get-ChildItem $OutputPath -Filter "SecureBoot_Summary_*.csv" -EA SilentlyContinue | Sort-Object Name
            foreach ($summCsv in $localSummaries) {
                try {
                    $summ = Import-Csv $summCsv.FullName | Select-Object -First 1
                    if ($summ.TotalDevices -and [int]$summ.TotalDevices -gt 0 -and $summ.ReportGeneratedAt) {
                        $dateStr = ([datetime]$summ.ReportGeneratedAt).ToString("yyyy-MM-dd")
                        $updated = if ($summ.Updated) { [int]$summ.Updated } else { 0 }
                        $notUpd = if ($summ.NotUptodate) { [int]$summ.NotUptodate } else { [int]$summ.TotalDevices - $updated }
                        $dailyData[$dateStr] = [PSCustomObject]@{
                            Date = $dateStr; Total = [int]$summ.TotalDevices; Updated = $updated; NotUpdated = $notUpd
                            NeedsReboot = 0; Errors = 0; ActionRequired = if ($summ.ActionRequired) { [int]$summ.ActionRequired } else { 0 }
                        }
                    }
                } catch { }
            }
            
            # Source 2: Old timestamped Aggregation_* folders (legacy, if they still exist)
            $aggFolders = Get-ChildItem $parentDir -Directory -Filter "Aggregation_*" -EA SilentlyContinue |
                Where-Object { $_.Name -match '^Aggregation_\d{8}' } |
                Sort-Object Name
            foreach ($folder in $aggFolders) {
                $summCsv = Get-ChildItem $folder.FullName -Filter "SecureBoot_Summary_*.csv" -EA SilentlyContinue | Select-Object -First 1
                if ($summCsv) {
                    try {
                        $summ = Import-Csv $summCsv.FullName | Select-Object -First 1
                        if ($summ.TotalDevices -and [int]$summ.TotalDevices -gt 0) {
                            $dateStr = $folder.Name -replace '^Aggregation_(\d{4})(\d{2})(\d{2})_.*', '$1-$2-$3'
                            $updated = if ($summ.Updated) { [int]$summ.Updated } else { 0 }
                            $notUpd = if ($summ.NotUptodate) { [int]$summ.NotUptodate } else { [int]$summ.TotalDevices - $updated }
                            $dailyData[$dateStr] = [PSCustomObject]@{
                                Date = $dateStr; Total = [int]$summ.TotalDevices; Updated = $updated; NotUpdated = $notUpd
                                NeedsReboot = 0; Errors = 0; ActionRequired = if ($summ.ActionRequired) { [int]$summ.ActionRequired } else { 0 }
                            }
                        }
                    } catch { }
                }
            }
            
            # Source 3: RolloutState.json WaveHistory (has per-wave timestamps from day 1)
            # This provides baseline data points even when no old aggregation folders exist
            $rolloutStatePaths = @(
                (Join-Path $parentDir "RolloutState\RolloutState.json"),
                (Join-Path $OutputPath "RolloutState\RolloutState.json")
            )
            foreach ($rsPath in $rolloutStatePaths) {
                if (Test-Path $rsPath) {
                    try {
                        $rsData = Get-Content $rsPath -Raw | ConvertFrom-Json
                        if ($rsData.WaveHistory) {
                            # Use wave start dates as trend data points
                            # Calculate cumulative devices targeted at each wave
                            $cumulativeTargeted = 0
                            foreach ($wave in $rsData.WaveHistory) {
                                if ($wave.StartedAt -and $wave.DeviceCount) {
                                    $waveDate = ([datetime]$wave.StartedAt).ToString("yyyy-MM-dd")
                                    $cumulativeTargeted += [int]$wave.DeviceCount
                                    if (-not $dailyData.ContainsKey($waveDate)) {
                                        # Approximate: at wave start time, only devices from prior waves were updated
                                        $dailyData[$waveDate] = [PSCustomObject]@{
                                            Date = $waveDate; Total = $c.Total; Updated = [math]::Max(0, $cumulativeTargeted - [int]$wave.DeviceCount)
                                            NotUpdated = $c.Total - [math]::Max(0, $cumulativeTargeted - [int]$wave.DeviceCount)
                                            NeedsReboot = 0; Errors = 0; ActionRequired = 0
                                        }
                                    }
                                }
                            }
                        }
                    } catch { }
                    break  # Use first found
                }
            }

            if ($dailyData.Count -gt 0) {
                $historyData = @($dailyData.GetEnumerator() | Sort-Object Key | ForEach-Object { $_.Value })
                Write-Host "   Bootstrapped $($historyData.Count) data points from historical summaries" -ForegroundColor Green
            }
        }

        # Add current data point (deduplicate by day - keep latest per day)
        $todayKey = (Get-Date).ToString("yyyy-MM-dd")
        $existingToday = $historyData | Where-Object { "$($_.Date)" -like "$todayKey*" }
        if ($existingToday) {
            # Replace today's entry
            $historyData = @($historyData | Where-Object { "$($_.Date)" -notlike "$todayKey*" })
        }
        $historyData += [PSCustomObject]@{
            Date = $todayKey
            Total = $c.Total
            Updated = $c.Updated
            NotUpdated = $stNotUptodate
            NeedsReboot = $c.NeedsReboot
            Errors = $c.WithErrors
            ActionRequired = $c.ActionReq
        }
        # Remove bad data points (0 total) and keep last 90
        $historyData = @($historyData | Where-Object { [int]$_.Total -gt 0 })
        # No cap — trend data is ~100 bytes/entry, a full year = ~36 KB
        $historyData | ConvertTo-Json -Depth 3 | Set-Content $historyPath -Encoding UTF8
        Write-Host "   Trend history: $($historyData.Count) data points" -ForegroundColor DarkGray
        
        # Build trend chart data for HTML
        $trendLabels = ($historyData | ForEach-Object { "'$($_.Date)'" }) -join ","
        $trendUpdated = ($historyData | ForEach-Object { $_.Updated }) -join ","
        $trendNotUpdated = ($historyData | ForEach-Object { $_.NotUpdated }) -join ","
        $trendTotal = ($historyData | ForEach-Object { $_.Total }) -join ","
        # Projection: extend trend line using exponential doubling (2,4,8,16...)
        # Derives wave size and observation period from actual trend history data.
        # - Wave size = largest single-period increase seen in history (the most recent wave deployed)
        # - Observation days = average calendar days between trend data points (how often we run)
        # Then doubles the wave size each period, matching the orchestrator's 2x growth strategy.
        $projLabels = ""; $projUpdated = ""; $projNotUpdated = ""; $hasProjection = $false
        if ($historyData.Count -ge 2) {
            $lastUpdated = $c.Updated
            $remaining = $stNotUptodate  # Only SB-ON not-updated devices (excludes SecureBoot OFF)
            $projDates = @(); $projValues = @(); $projNotUpdValues = @()
            $projDate = Get-Date

            # Derive wave size and observation period from trend history
            $increments = @()
            $dayGaps = @()
            for ($hi = 1; $hi -lt $historyData.Count; $hi++) {
                $inc = $historyData[$hi].Updated - $historyData[$hi-1].Updated
                if ($inc -gt 0) { $increments += $inc }
                try {
                    $d1 = [datetime]::Parse($historyData[$hi-1].Date)
                    $d2 = [datetime]::Parse($historyData[$hi].Date)
                    $gap = ($d2 - $d1).TotalDays
                    if ($gap -gt 0) { $dayGaps += $gap }
                } catch {}
            }
            # Wave size = most recent positive increment (current wave), fallback to average, minimum 2
            $waveSize = if ($increments.Count -gt 0) {
                [math]::Max(2, $increments[-1])
            } else { 2 }
            # Observation period = average gap between data points (calendar days per wave), minimum 1
            $waveDays = if ($dayGaps.Count -gt 0) {
                [math]::Max(1, [math]::Round(($dayGaps | Measure-Object -Average).Average, 0))
            } else { 1 }

            Write-Host "   Projection: waveSize=$waveSize (from last increment), waveDays=$waveDays (avg gap from history)" -ForegroundColor DarkGray

            $dayCounter = 0
            # Project until all devices updated or 365 days max
            for ($pi = 1; $pi -le 365; $pi++) {
                $projDate = $projDate.AddDays(1)
                $dayCounter++
                # At each observation period boundary, deploy a wave then double
                if ($dayCounter -ge $waveDays) {
                    $devicesThisWave = [math]::Min($waveSize, $remaining)
                    $lastUpdated += $devicesThisWave
                    $remaining -= $devicesThisWave
                    if ($lastUpdated -gt ($c.Updated + $stNotUptodate)) { $lastUpdated = $c.Updated + $stNotUptodate; $remaining = 0 }
                    # Double wave size for next period (orchestrator 2x strategy)
                    $waveSize = $waveSize * 2
                    $dayCounter = 0
                }
                $projDates += "'$($projDate.ToString("yyyy-MM-dd"))'"
                $projValues += $lastUpdated
                $projNotUpdValues += [math]::Max(0, $remaining)
                if ($remaining -le 0) { break }
            }
            $projLabels = $projDates -join ","
            $projUpdated = $projValues -join ","
            $projNotUpdated = $projNotUpdValues -join ","
            $hasProjection = $projDates.Count -gt 0
        } elseif ($historyData.Count -eq 1) {
            Write-Host "   Projection: need at least 2 trend data points to derive wave timing" -ForegroundColor DarkGray
        }
        # Build combined chart data strings for the here-string
        $allChartLabels = if ($hasProjection) { "$trendLabels,$projLabels" } else { $trendLabels }
        $projDataJS = if ($hasProjection) { $projUpdated } else { "" }
        $projNotUpdJS = if ($hasProjection) { $projNotUpdated } else { "" }
        $histCount = ($historyData | Measure-Object).Count
        $stMfrCounts.GetEnumerator() | Sort-Object { $_.Value.Total } -Descending | ForEach-Object {
            @{ name=$_.Key; total=$_.Value.Total; updated=$_.Value.Updated; highConf=$_.Value.HighConf; actionReq=$_.Value.ActionReq }
        } | ConvertTo-Json -Depth 3 | Set-Content (Join-Path $dataDir "manufacturers.json") -Encoding UTF8
        
        # Convert JSON data files to CSV for human-readable Excel downloads
        Write-Host "Converting device data to CSV for Excel download..." -ForegroundColor Gray
        foreach ($dfName in $stDeviceFiles) {
            $jsonFile = Join-Path $dataDir "$dfName.json"
            $csvFile = Join-Path $OutputPath "SecureBoot_${dfName}_$timestamp.csv"
            if (Test-Path $jsonFile) {
                try {
                    $jsonData = Get-Content $jsonFile -Raw | ConvertFrom-Json
                    if ($jsonData.Count -gt 0) {
                        # Include extra columns for update_pending CSV
                        $selectProps = if ($dfName -eq "update_pending") {
                            @('HostName', 'WMI_Manufacturer', 'WMI_Model', 'BucketId', 'ConfidenceLevel', 'IsUpdated', 'UEFICA2023Status', 'UEFICA2023Error', 'AvailableUpdatesPolicy', 'WinCSKeyApplied', 'SecureBootTaskStatus')
                        } else {
                            @('HostName', 'WMI_Manufacturer', 'WMI_Model', 'BucketId', 'ConfidenceLevel', 'IsUpdated', 'UEFICA2023Error', 'SecureBootTaskStatus', 'KnownIssueId', 'SkipReasonKnownIssue')
                        }
                        $jsonData | Select-Object $selectProps |
                            Export-Csv -Path $csvFile -NoTypeInformation -Encoding UTF8
                        Write-Host "   $dfName -> $($jsonData.Count) rows -> CSV" -ForegroundColor DarkGray
                    }
                } catch { Write-Host "   $dfName - skipped" -ForegroundColor DarkYellow }
            }
        }
        
        # Generate self-contained HTML dashboard
        $htmlPath = Join-Path $OutputPath "SecureBoot_Dashboard_$timestamp.html"
        Write-Host "Generating self-contained HTML dashboard..." -ForegroundColor Yellow
        
        # VELOCITY PROJECTION: Calculate from scan history or previous summary
        $stDeadline = [datetime]"2026-06-24"  # KEK cert expiry
        $stDaysToDeadline = [math]::Max(0, ($stDeadline - (Get-Date)).Days)
        $stDevicesPerDay = 0
        $stProjectedDate = $null
        $stVelocitySource = "N/A"
        $stWorkingDays = 0
        $stCalendarDays = 0
        
        # Try trend history first (lightweight, already maintained by aggregator — replaces bloated ScanHistory.json)
        if ($historyData.Count -ge 2) {
            $validHistory = @($historyData | Where-Object { [int]$_.Total -gt 0 -and [int]$_.Updated -ge 0 })
            if ($validHistory.Count -ge 2) {
                $prev = $validHistory[-2]; $curr = $validHistory[-1]
                $prevDate = [datetime]::Parse($prev.Date.Substring(0, [Math]::Min(10, $prev.Date.Length)))
                $currDate = [datetime]::Parse($curr.Date.Substring(0, [Math]::Min(10, $curr.Date.Length)))
                $daysDiff = ($currDate - $prevDate).TotalDays
                if ($daysDiff -gt 0) {
                    $updDiff = [int]$curr.Updated - [int]$prev.Updated
                    if ($updDiff -gt 0) {
                        $stDevicesPerDay = [math]::Round($updDiff / $daysDiff, 0)
                        $stVelocitySource = "TrendHistory"
                    }
                }
            }
        }
        
        # Try orchestrator rollout summary (has pre-computed velocity)
        if ($stVelocitySource -eq "N/A" -and $RolloutSummaryPath -and (Test-Path $RolloutSummaryPath)) {
            try {
                $rolloutSummary = Get-Content $RolloutSummaryPath -Raw | ConvertFrom-Json
                if ($rolloutSummary.DevicesPerDay -and [double]$rolloutSummary.DevicesPerDay -gt 0) {
                    $stDevicesPerDay = [math]::Round([double]$rolloutSummary.DevicesPerDay, 1)
                    $stVelocitySource = "Orchestrator"
                    if ($rolloutSummary.ProjectedCompletionDate) {
                        $stProjectedDate = $rolloutSummary.ProjectedCompletionDate
                    }
                    if ($rolloutSummary.WorkingDaysRemaining) { $stWorkingDays = [int]$rolloutSummary.WorkingDaysRemaining }
                    if ($rolloutSummary.CalendarDaysRemaining) { $stCalendarDays = [int]$rolloutSummary.CalendarDaysRemaining }
                }
            } catch { }
        }
        
        # Fallback: try previous summary CSV (search current folder AND parent/sibling aggregation folders)
        if ($stVelocitySource -eq "N/A") {
            $searchPaths = @(
                (Join-Path $OutputPath "SecureBoot_Summary_*.csv")
            )
            # Also search sibling aggregation folders (orchestrator creates new folder each run)
            $parentPath = Split-Path $OutputPath -Parent
            if ($parentPath) {
                $searchPaths += (Join-Path $parentPath "Aggregation_*\SecureBoot_Summary_*.csv")
                $searchPaths += (Join-Path $parentPath "SecureBoot_Summary_*.csv")
            }
            $prevSummary = $searchPaths | ForEach-Object { Get-ChildItem $_ -EA SilentlyContinue } | Sort-Object LastWriteTime -Descending | Select-Object -First 1
            if ($prevSummary) {
                try {
                    $prevStats = Get-Content $prevSummary.FullName | ConvertFrom-Csv
                    $prevDate = [datetime]$prevStats.ReportGeneratedAt
                    $daysSinceLast = ((Get-Date) - $prevDate).TotalDays
                    if ($daysSinceLast -gt 0.01) {
                        $prevUpdated = [int]$prevStats.Updated
                        $updDelta = $c.Updated - $prevUpdated
                        if ($updDelta -gt 0) {
                            $stDevicesPerDay = [math]::Round($updDelta / $daysSinceLast, 0)
                            $stVelocitySource = "PreviousReport"
                        }
                    }
                } catch { }
            }
        }
        
        # Fallback: calculate velocity from full trend history span (first vs latest data point)
        if ($stVelocitySource -eq "N/A" -and $historyData.Count -ge 2) {
            $validHistory = @($historyData | Where-Object { [int]$_.Total -gt 0 -and [int]$_.Updated -ge 0 })
            if ($validHistory.Count -ge 2) {
                $first = $validHistory[0]
                $last = $validHistory[-1]
                $firstDate = [datetime]::Parse($first.Date.Substring(0, [Math]::Min(10, $first.Date.Length)))
                $lastDate = [datetime]::Parse($last.Date.Substring(0, [Math]::Min(10, $last.Date.Length)))
                $daysDiff = ($lastDate - $firstDate).TotalDays
                if ($daysDiff -gt 0) {
                    $updDiff = [int]$last.Updated - [int]$first.Updated
                    if ($updDiff -gt 0) {
                        $stDevicesPerDay = [math]::Round($updDiff / $daysDiff, 1)
                        $stVelocitySource = "TrendHistory"
                    }
                }
            }
        }
        
        # Calculate projection using exponential doubling (consistent with trend chart)
        # Reuse the projection data already computed for the chart if available
        if ($hasProjection -and $projDates.Count -gt 0) {
            # Use the last projected date (when all devices are updated)
            $lastProjDateStr = $projDates[-1] -replace "'", ""
            $stProjectedDate = ([datetime]::Parse($lastProjDateStr)).ToString("MMM dd, yyyy")
            $stCalendarDays = ([datetime]::Parse($lastProjDateStr) - (Get-Date)).Days
            $stWorkingDays = 0
            $d = Get-Date
            for ($i = 0; $i -lt $stCalendarDays; $i++) {
                $d = $d.AddDays(1)
                if ($d.DayOfWeek -ne 'Saturday' -and $d.DayOfWeek -ne 'Sunday') { $stWorkingDays++ }
            }
        } elseif ($stDevicesPerDay -gt 0 -and $stNotUptodate -gt 0) {
            # Fallback: linear projection if no exponential data available
            $daysNeeded = [math]::Ceiling($stNotUptodate / $stDevicesPerDay)
            $stProjectedDate = (Get-Date).AddDays($daysNeeded).ToString("MMM dd, yyyy")
            $stWorkingDays = 0; $stCalendarDays = $daysNeeded
            $d = Get-Date
            for ($i = 0; $i -lt $daysNeeded; $i++) {
                $d = $d.AddDays(1)
                if ($d.DayOfWeek -ne 'Saturday' -and $d.DayOfWeek -ne 'Sunday') { $stWorkingDays++ }
            }
        }
        
        # Build velocity HTML
        $velocityHtml = if ($stDevicesPerDay -gt 0) {
            "<div><strong>&#128640; Devices/Day:</strong> $($stDevicesPerDay.ToString('N0')) (source: $stVelocitySource)</div>" +
            "<div><strong>&#128197; Projected Completion:</strong> $stProjectedDate" +
            $(if ($stProjectedDate -and [datetime]::Parse($stProjectedDate) -gt $stDeadline) { " <span style='color:#dc3545;font-weight:bold'>&#9888; PAST DEADLINE</span>" } else { " <span style='color:#28a745'>&#10003; Before deadline</span>" }) +
            "</div>" +
            "<div><strong>&#128336; Working Days:</strong> $stWorkingDays | <strong>Calendar Days:</strong> $stCalendarDays</div>" +
            "<div style='font-size:.8em;color:#888'>Deadline: Jun 24, 2026 (KEK certificate expiry) | Days remaining: $stDaysToDeadline</div>"
        } else {
            "<div style='padding:8px;background:#fff3cd;border-radius:4px;border-left:3px solid #ffc107'>" +
            "<strong>&#128197; Projected Completion:</strong> Insufficient data for velocity calculation. " +
            "Run aggregation at least twice with data changes to establish a rate.<br/>" +
            "<strong>Deadline:</strong> Jun 24, 2026 (KEK certificate expiry) | <strong>Days remaining:</strong> $stDaysToDeadline</div>"
        }
        
        # Cert expiry countdown
        $certToday = Get-Date
        $certKekExpiry = [datetime]"2026-06-24"
        $certUefiExpiry = [datetime]"2026-06-27"
        $certPcaExpiry = [datetime]"2026-10-19"
        $daysToKek = [math]::Max(0, ($certKekExpiry - $certToday).Days)
        $daysToUefi = [math]::Max(0, ($certUefiExpiry - $certToday).Days)
        $daysToPca = [math]::Max(0, ($certPcaExpiry - $certToday).Days)
        $certUrgency = if ($daysToKek -lt 30) { '#dc3545' } elseif ($daysToKek -lt 90) { '#fd7e14' } else { '#28a745' }
        
        # Helper: Read records from JSON, build bucket summary + first N device rows
        $maxInlineRows = 200
        function Build-InlineTable {
            param([string]$JsonPath, [int]$MaxRows = 200, [string]$CsvFileName = "")
            $bucketSummary = ""
            $deviceRows = ""
            $totalCount = 0
            if (Test-Path $JsonPath) {
                try {
                    $data = Get-Content $JsonPath -Raw | ConvertFrom-Json
                    $totalCount = $data.Count
                    
                    # BUCKET SUMMARY: Group by BucketId, show counts per bucket with Updated from global bucket stats
                    if ($totalCount -gt 0) {
                        $buckets = $data | Group-Object BucketId | Sort-Object Count -Descending
                        $bucketSummary = "<h3 style='font-size:.95em;color:#333;margin:10px 0 5px'>By Hardware Bucket ($($buckets.Count) buckets)</h3>"
                        $bucketSummary += "<div style='max-height:300px;overflow-y:auto;margin-bottom:15px'><table><thead><tr><th>BucketID</th><th style='text-align:right'>Total</th><th style='text-align:right;color:#28a745'>Updated</th><th style='text-align:right;color:#dc3545'>Not Updated</th><th>Manufacturer</th></tr></thead><tbody>"
                        foreach ($b in $buckets) {
                            $bid = if ($b.Name) { $b.Name } else { "(empty)" }
                            $mfr = ($b.Group | Select-Object -First 1).WMI_Manufacturer
                            # Get Updated count from global bucket stats (all devices in this bucket across the entire dataset)
                            $lookupKey = $bid
                            $globalBucket = if ($stAllBuckets.ContainsKey($lookupKey)) { $stAllBuckets[$lookupKey] } else { $null }
                            $bUpdatedGlobal = if ($globalBucket) { $globalBucket.Updated } else { 0 }
                            $bTotalGlobal = if ($globalBucket) { $globalBucket.Count } else { $b.Count }
                            $bNotUpdatedGlobal = $bTotalGlobal - $bUpdatedGlobal
                            $bucketSummary += "<tr><td style='font-size:.8em'>$bid</td><td style='text-align:right;font-weight:bold'>$bTotalGlobal</td><td style='text-align:right;color:#28a745;font-weight:bold'>$bUpdatedGlobal</td><td style='text-align:right;color:#dc3545;font-weight:bold'>$bNotUpdatedGlobal</td><td>$mfr</td></tr>`n"
                        }
                        $bucketSummary += "</tbody></table></div>"
                    }
                    
                    # DEVICE DETAIL: First N rows as flat list
                    $slice = $data | Select-Object -First $MaxRows
                    foreach ($d in $slice) {
                        $conf = $d.ConfidenceLevel
                        $confBadge = if ($conf -match "High") { '<span class="badge badge-success">High Conf</span>' }
                                     elseif ($conf -match "Not Sup") { '<span class="badge badge-danger">Not Supported</span>' }
                                     elseif ($conf -match "Under") { '<span class="badge badge-info">Under Obs</span>' }
                                     elseif ($conf -match "Paused") { '<span class="badge badge-warning">Paused</span>' }
                                     else { '<span class="badge badge-warning">Action Req</span>' }
                        $statusBadge = if ($d.IsUpdated) { '<span class="badge badge-success">Updated</span>' }
                                       elseif ($d.UEFICA2023Error) { '<span class="badge badge-danger">Error</span>' }
                                       else { '<span class="badge badge-warning">Pending</span>' }
                        $deviceRows += "<tr><td>$($d.HostName)</td><td>$($d.WMI_Manufacturer)</td><td>$($d.WMI_Model)</td><td>$confBadge</td><td>$statusBadge</td><td>$(if($d.UEFICA2023Error){$d.UEFICA2023Error}else{'-'})</td><td style='font-size:.75em'>$($d.BucketId)</td></tr>`n"
                    }
                } catch { }
            }
            if ($totalCount -eq 0) {
                return "<div style='padding:20px;color:#888;font-style:italic'>No devices in this category.</div>"
            }
            $showing = [math]::Min($MaxRows, $totalCount)
            $header = "<div style='margin:5px 0;font-size:.85em;color:#666'>Total: $($totalCount.ToString("N0")) devices"
            if ($CsvFileName) { $header += " | <a href='$CsvFileName' style='color:#1a237e;font-weight:bold'>&#128196; Download Full CSV for Excel</a>" }
            $header += "</div>"
            $deviceHeader = "<h3 style='font-size:.95em;color:#333;margin:10px 0 5px'>Device Details (showing first $showing)</h3>"
            $deviceTable = "<div style='max-height:500px;overflow-y:auto'><table><thead><tr><th>HostName</th><th>Manufacturer</th><th>Model</th><th>Confidence</th><th>Status</th><th>Error</th><th>BucketId</th></tr></thead><tbody>$deviceRows</tbody></table></div>"
            return "$header$bucketSummary$deviceHeader$deviceTable"
        }
        
        # Build inline tables from the JSON files already on disk, linking to CSVs
        $tblErrors = Build-InlineTable -JsonPath (Join-Path $dataDir "errors.json") -MaxRows $maxInlineRows -CsvFileName "SecureBoot_errors_$timestamp.csv"
        $tblKI = Build-InlineTable -JsonPath (Join-Path $dataDir "known_issues.json") -MaxRows $maxInlineRows -CsvFileName "SecureBoot_known_issues_$timestamp.csv"
        $tblKEK = Build-InlineTable -JsonPath (Join-Path $dataDir "missing_kek.json") -MaxRows $maxInlineRows -CsvFileName "SecureBoot_missing_kek_$timestamp.csv"
        $tblNotUpd = Build-InlineTable -JsonPath (Join-Path $dataDir "not_updated.json") -MaxRows $maxInlineRows -CsvFileName "SecureBoot_not_updated_$timestamp.csv"
        $tblTaskDis = Build-InlineTable -JsonPath (Join-Path $dataDir "task_disabled.json") -MaxRows $maxInlineRows -CsvFileName "SecureBoot_task_disabled_$timestamp.csv"
        $tblTemp = Build-InlineTable -JsonPath (Join-Path $dataDir "temp_failures.json") -MaxRows $maxInlineRows -CsvFileName "SecureBoot_temp_failures_$timestamp.csv"
        $tblPerm = Build-InlineTable -JsonPath (Join-Path $dataDir "perm_failures.json") -MaxRows $maxInlineRows -CsvFileName "SecureBoot_perm_failures_$timestamp.csv"
        $tblUpdated = Build-InlineTable -JsonPath (Join-Path $dataDir "updated_devices.json") -MaxRows $maxInlineRows -CsvFileName "SecureBoot_updated_devices_$timestamp.csv"
        $tblActionReq = Build-InlineTable -JsonPath (Join-Path $dataDir "action_required.json") -MaxRows $maxInlineRows -CsvFileName "SecureBoot_action_required_$timestamp.csv"
        $tblUnderObs = Build-InlineTable -JsonPath (Join-Path $dataDir "under_observation.json") -MaxRows $maxInlineRows -CsvFileName "SecureBoot_under_observation_$timestamp.csv"
        $tblNeedsReboot = Build-InlineTable -JsonPath (Join-Path $dataDir "needs_reboot.json") -MaxRows $maxInlineRows -CsvFileName "SecureBoot_needs_reboot_$timestamp.csv"
        $tblSBOff = Build-InlineTable -JsonPath (Join-Path $dataDir "secureboot_off.json") -MaxRows $maxInlineRows -CsvFileName "SecureBoot_secureboot_off_$timestamp.csv"
        $tblRolloutIP = Build-InlineTable -JsonPath (Join-Path $dataDir "rollout_inprogress.json") -MaxRows $maxInlineRows -CsvFileName "SecureBoot_rollout_inprogress_$timestamp.csv"
        # Custom table for Update Pending — includes UEFICA2023Status and UEFICA2023Error columns
        $tblUpdatePending = ""
        $upJsonPath = Join-Path $dataDir "update_pending.json"
        if (Test-Path $upJsonPath) {
            try {
                $upData = Get-Content $upJsonPath -Raw | ConvertFrom-Json
                $upCount = $upData.Count
                if ($upCount -gt 0) {
                    $upHeader = "<div style='margin:5px 0;font-size:.85em;color:#666'>Total: $($upCount.ToString("N0")) devices | <a href='SecureBoot_update_pending_$timestamp.csv' style='color:#1a237e;font-weight:bold'>&#128196; Download Full CSV for Excel</a></div>"
                    $upRows = ""
                    $upSlice = $upData | Select-Object -First $maxInlineRows
                    foreach ($d in $upSlice) {
                        $uefiSt = if ($d.UEFICA2023Status) { $d.UEFICA2023Status } else { '<span style="color:#999">null</span>' }
                        $uefiErr = if ($d.UEFICA2023Error) { "<span style='color:#dc3545'>$($d.UEFICA2023Error)</span>" } else { '-' }
                        $policyVal = if ($d.AvailableUpdatesPolicy) { $d.AvailableUpdatesPolicy } else { '-' }
                        $wincsVal = if ($d.WinCSKeyApplied) { '<span class="badge badge-success">Yes</span>' } else { '-' }
                        $upRows += "<tr><td>$($d.HostName)</td><td>$($d.WMI_Manufacturer)</td><td>$($d.WMI_Model)</td><td>$uefiSt</td><td>$uefiErr</td><td>$policyVal</td><td>$wincsVal</td><td style='font-size:.75em'>$($d.BucketId)</td></tr>`n"
                    }
                    $upShowing = [math]::Min($maxInlineRows, $upCount)
                    $upDevHeader = "<h3 style='font-size:.95em;color:#333;margin:10px 0 5px'>Device Details (showing first $upShowing)</h3>"
                    $upTable = "<div style='max-height:500px;overflow-y:auto'><table><thead><tr><th>HostName</th><th>Manufacturer</th><th>Model</th><th>UEFICA2023Status</th><th>UEFICA2023Error</th><th>Policy</th><th>WinCS Key</th><th>BucketId</th></tr></thead><tbody>$upRows</tbody></table></div>"
                    $tblUpdatePending = "$upHeader$upDevHeader$upTable"
                } else {
                    $tblUpdatePending = "<div style='padding:20px;color:#888;font-style:italic'>No devices in this category.</div>"
                }
            } catch {
                $tblUpdatePending = "<div style='padding:20px;color:#888;font-style:italic'>No devices in this category.</div>"
            }
        } else {
            $tblUpdatePending = "<div style='padding:20px;color:#888;font-style:italic'>No devices in this category.</div>"
        }
        
        # Cert expiry countdown
        $certToday = Get-Date
        $certKekExpiry = [datetime]"2026-06-24"
        $certUefiExpiry = [datetime]"2026-06-27"
        $certPcaExpiry = [datetime]"2026-10-19"
        $daysToKek = [math]::Max(0, ($certKekExpiry - $certToday).Days)
        $daysToUefi = [math]::Max(0, ($certUefiExpiry - $certToday).Days)
        $daysToPca = [math]::Max(0, ($certPcaExpiry - $certToday).Days)
        $certUrgency = if ($daysToKek -lt 30) { '#dc3545' } elseif ($daysToKek -lt 90) { '#fd7e14' } else { '#28a745' }
        
        # Build manufacturer chart data inline (Top 10 by device count)
        $mfrSorted = $stMfrCounts.GetEnumerator() | Sort-Object { $_.Value.Total } -Descending | Select-Object -First 10
        $mfrChartTitle = if ($stMfrCounts.Count -le 10) { "By Manufacturer" } else { "Top 10 Manufacturers" }
        $mfrLabels = ($mfrSorted | ForEach-Object { "'$($_.Key)'" }) -join ","
        $mfrUpdated = ($mfrSorted | ForEach-Object { $_.Value.Updated }) -join ","
        $mfrUpdatePending = ($mfrSorted | ForEach-Object { $_.Value.UpdatePending }) -join ","
        $mfrHighConf = ($mfrSorted | ForEach-Object { $_.Value.HighConf }) -join ","
        $mfrUnderObs = ($mfrSorted | ForEach-Object { $_.Value.UnderObs }) -join ","
        $mfrActionReq = ($mfrSorted | ForEach-Object { $_.Value.ActionReq }) -join ","
        $mfrTempPaused = ($mfrSorted | ForEach-Object { $_.Value.TempPaused }) -join ","
        $mfrNotSupported = ($mfrSorted | ForEach-Object { $_.Value.NotSupported }) -join ","
        $mfrSBOff = ($mfrSorted | ForEach-Object { $_.Value.SBOff }) -join ","
        $mfrWithErrors = ($mfrSorted | ForEach-Object { $_.Value.WithErrors }) -join ","
        
        # Build manufacturer table
        $mfrTableRows = ""
        $stMfrCounts.GetEnumerator() | Sort-Object { $_.Value.Total } -Descending | ForEach-Object {
            $mfrTableRows += "<tr><td>$($_.Key)</td><td>$($_.Value.Total.ToString("N0"))</td><td>$($_.Value.Updated.ToString("N0"))</td><td>$($_.Value.HighConf.ToString("N0"))</td><td>$($_.Value.ActionReq.ToString("N0"))</td></tr>`n"
        }
        
        $htmlContent = @"
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Secure Boot Certificate Status Dashboard</title>
<script src="https://cdn.jsdelivr.net/npm/chart.js"></script>
<style>
*{box-sizing:border-box;margin:0;padding:0}
body{font-family:'Segoe UI',Tahoma,sans-serif;background:#f0f2f5;color:#333}
.header{background:linear-gradient(135deg,#1a237e,#0d47a1);color:#fff;padding:20px 30px}
.header h1{font-size:1.6em;margin-bottom:5px}
.header .meta{font-size:.85em;opacity:.9}
.container{max-width:1400px;margin:0 auto;padding:20px}
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(170px,1fr));gap:12px;margin:20px 0}
.card{background:#fff;border-radius:10px;padding:15px;box-shadow:0 2px 8px rgba(0,0,0,.08);border-left:4px solid #ccc;transition:transform .2s}
.card:hover{transform:translateY(-2px);box-shadow:0 4px 15px rgba(0,0,0,.12)}
.card .value{font-size:1.8em;font-weight:700}
.card .label{font-size:.8em;color:#666;margin-top:4px}
.card .pct{font-size:.75em;color:#888}
.section{background:#fff;border-radius:10px;padding:20px;margin:15px 0;box-shadow:0 2px 8px rgba(0,0,0,.08)}
.section h2{font-size:1.2em;color:#1a237e;margin-bottom:10px;cursor:pointer;user-select:none}
.section h2:hover{text-decoration:underline}
.section-body{display:none}
.section-body.open{display:block}
.charts{display:grid;grid-template-columns:1fr 1fr;gap:20px;margin:20px 0}
.chart-box{background:#fff;border-radius:10px;padding:20px;box-shadow:0 2px 8px rgba(0,0,0,.08)}
table{width:100%;border-collapse:collapse;font-size:.85em}
th{background:#e8eaf6;padding:8px 10px;text-align:left;position:sticky;top:0;z-index:1}
td{padding:6px 10px;border-bottom:1px solid #eee}
tr:hover{background:#f5f5f5}
.badge{display:inline-block;padding:2px 8px;border-radius:10px;font-size:.75em;font-weight:700}
.badge-success{background:#d4edda;color:#155724}
.badge-danger{background:#f8d7da;color:#721c24}
.badge-warning{background:#fff3cd;color:#856404}
.badge-info{background:#d1ecf1;color:#0c5460}
.top-link{float:right;font-size:.8em;color:#1a237e;text-decoration:none}
.footer{text-align:center;padding:20px;color:#999;font-size:.8em}
a{color:#1a237e}
</style>
</head>
<body>
<div class="header">
    <h1>Secure Boot Certificate Status Dashboard</h1>
    <div class="meta">Generated: $($stats.ReportGeneratedAt) | Total Devices: $($c.Total.ToString("N0")) | Unique Buckets: $($stAllBuckets.Count)</div>
</div>
<div class="container">

<!-- KPI Cards - clickable, linked to sections -->
<div class="cards">
    <a class="card" href="#s-nu" onclick="openSection('d-nu')" style="border-left-color:#dc3545;text-decoration:none;position:relative"><div style="position:absolute;top:8px;right:8px;background:#dc3545;color:#fff;padding:1px 6px;border-radius:8px;font-size:.65em;font-weight:700">PRIMARY</div><div class="value" style="color:#dc3545">$($stNotUptodate.ToString("N0"))</div><div class="label">NOT UPDATED</div><div class="pct">$($stats.PercentNotUptodate)% - NEEDS ACTION</div></a>
    <a class="card" href="#s-upd" onclick="openSection('d-upd')" style="border-left-color:#28a745;text-decoration:none;position:relative"><div style="position:absolute;top:8px;right:8px;background:#28a745;color:#fff;padding:1px 6px;border-radius:8px;font-size:.65em;font-weight:700">PRIMARY</div><div class="value" style="color:#28a745">$($c.Updated.ToString("N0"))</div><div class="label">Updated</div><div class="pct">$($stats.PercentCertUpdated)%</div></a>
    <a class="card" href="#s-sboff" onclick="openSection('d-sboff')" style="border-left-color:#6c757d;text-decoration:none;position:relative"><div style="position:absolute;top:8px;right:8px;background:#6c757d;color:#fff;padding:1px 6px;border-radius:8px;font-size:.65em;font-weight:700">PRIMARY</div><div class="value">$($c.SBOff.ToString("N0"))</div><div class="label">SecureBoot OFF</div><div class="pct">$(if($c.Total -gt 0){[math]::Round(($c.SBOff/$c.Total)*100,1)}else{0})% - Out of Scope</div></a>
    <a class="card" href="#s-nrb" onclick="openSection('d-nrb')" style="border-left-color:#ffc107;text-decoration:none"><div class="value" style="color:#ffc107">$($c.NeedsReboot.ToString("N0"))</div><div class="label">Needs Reboot</div><div class="pct">$(if($c.Total -gt 0){[math]::Round(($c.NeedsReboot/$c.Total)*100,1)}else{0})% - awaiting reboot</div></a>
    <a class="card" href="#s-upd-pend" onclick="openSection('d-upd-pend')" style="border-left-color:#6f42c1;text-decoration:none"><div class="value" style="color:#6f42c1">$($c.UpdatePending.ToString("N0"))</div><div class="label">Update Pending</div><div class="pct">$(if($c.Total -gt 0){[math]::Round(($c.UpdatePending/$c.Total)*100,1)}else{0})% - Policy/WinCS applied, awaiting update</div></a>
    <a class="card" href="#s-rip" onclick="openSection('d-rip')" style="border-left-color:#17a2b8;text-decoration:none"><div class="value">$($c.RolloutInProgress)</div><div class="label">Rollout In Progress</div><div class="pct">$(if($c.Total -gt 0){[math]::Round(($c.RolloutInProgress/$c.Total)*100,1)}else{0})%</div></a>
    <a class="card" href="#s-nu" onclick="openSection('d-nu')" style="border-left-color:#28a745;text-decoration:none"><div class="value" style="color:#28a745">$($c.HighConf.ToString("N0"))</div><div class="label">High Confidence</div><div class="pct">$($stats.PercentHighConfidence)% - Safe for rollout</div></a>
    <a class="card" href="#s-uo" onclick="openSection('d-uo')" style="border-left-color:#17a2b8;text-decoration:none"><div class="value" style="color:#ffc107">$($c.UnderObs.ToString("N0"))</div><div class="label">Under Observation</div><div class="pct">$(if($c.Total -gt 0){[math]::Round(($c.UnderObs/$c.Total)*100,1)}else{0})%</div></a>
    <a class="card" href="#s-ar" onclick="openSection('d-ar')" style="border-left-color:#fd7e14;text-decoration:none"><div class="value" style="color:#fd7e14">$($c.ActionReq.ToString("N0"))</div><div class="label">Action Required</div><div class="pct">$($stats.PercentActionRequired)% - must test</div></a>
    <a class="card" href="#s-err" onclick="openSection('d-err')" style="border-left-color:#dc3545;text-decoration:none"><div class="value" style="color:#dc3545">$($stAtRisk.ToString("N0"))</div><div class="label">At Risk</div><div class="pct">$($stats.PercentAtRisk)% - Similar to failed</div></a>
    <a class="card" href="#s-td" onclick="openSection('d-td')" style="border-left-color:#dc3545;text-decoration:none"><div class="value" style="color:#dc3545">$($c.TaskDisabled.ToString("N0"))</div><div class="label">Task Disabled</div><div class="pct">$(if($c.Total -gt 0){[math]::Round(($c.TaskDisabled/$c.Total)*100,1)}else{0})% - Blocked</div></a>
    <a class="card" href="#s-tf" onclick="openSection('d-tf')" style="border-left-color:#fd7e14;text-decoration:none"><div class="value" style="color:#fd7e14">$($c.TempPaused.ToString("N0"))</div><div class="label">Temp. Paused</div><div class="pct">$(if($c.Total -gt 0){[math]::Round(($c.TempPaused/$c.Total)*100,1)}else{0})%</div></a>
    <a class="card" href="#s-ki" onclick="openSection('d-ki')" style="border-left-color:#dc3545;text-decoration:none"><div class="value" style="color:#dc3545">$($c.WithKnownIssues.ToString("N0"))</div><div class="label">Known Issues</div><div class="pct">$(if($c.Total -gt 0){[math]::Round(($c.WithKnownIssues/$c.Total)*100,1)}else{0})%</div></a>
    <a class="card" href="#s-kek" onclick="openSection('d-kek')" style="border-left-color:#fd7e14;text-decoration:none"><div class="value" style="color:#fd7e14">$($c.WithMissingKEK.ToString("N0"))</div><div class="label">Missing KEK</div><div class="pct">$(if($c.Total -gt 0){[math]::Round(($c.WithMissingKEK/$c.Total)*100,1)}else{0})%</div></a>
    <a class="card" href="#s-err" onclick="openSection('d-err')" style="border-left-color:#dc3545;text-decoration:none"><div class="value" style="color:#dc3545">$($c.WithErrors.ToString("N0"))</div><div class="label">With Errors</div><div class="pct">$($stats.PercentWithErrors)% - UEFI errors</div></a>
    <a class="card" href="#s-tf" onclick="openSection('d-tf')" style="border-left-color:#dc3545;text-decoration:none"><div class="value" style="color:#dc3545">$($c.TempFailures.ToString("N0"))</div><div class="label">Temp. Failures</div><div class="pct">$(if($c.Total -gt 0){[math]::Round(($c.TempFailures/$c.Total)*100,1)}else{0})%</div></a>
    <a class="card" href="#s-pf" onclick="openSection('d-pf')" style="border-left-color:#721c24;text-decoration:none"><div class="value" style="color:#721c24">$($c.PermFailures.ToString("N0"))</div><div class="label">Not Supported</div><div class="pct">$(if($c.Total -gt 0){[math]::Round(($c.PermFailures/$c.Total)*100,1)}else{0})%</div></a>
</div>

<!-- Deployment Velocity & Cert Expiry -->
<div id="s-velocity" style="display:grid;grid-template-columns:1fr 1fr;gap:20px;margin:15px 0">
<div class="section" style="margin:0">
    <h2>&#128197; Deployment Velocity</h2>
    <div class="section-body open">
        <div style="font-size:2.5em;font-weight:700;color:#28a745">$($c.Updated.ToString("N0"))</div>
        <div style="color:#666">devices updated out of $($c.Total.ToString("N0"))</div>
        <div style="margin:10px 0;background:#e8eaf6;height:20px;border-radius:10px;overflow:hidden"><div style="background:#28a745;height:100%;width:$($stats.PercentCertUpdated)%;border-radius:10px"></div></div>
        <div style="font-size:.8em;color:#888">$($stats.PercentCertUpdated)% complete</div>
        <div style="margin-top:10px;padding:10px;background:#f8f9fa;border-radius:8px;font-size:.85em">
            <div><strong>Remaining:</strong> $($stNotUptodate.ToString("N0")) devices need action</div>
            <div><strong>Blocking:</strong> $($c.WithErrors + $c.PermFailures + $c.TaskDisabledNotUpdated) devices (errors + permanent + task disabled)</div>
            <div><strong>Safe to deploy:</strong> $($stSafeList.ToString("N0")) devices (same bucket as successful)</div>
            $velocityHtml
        </div>
    </div>
</div>
<div class="section" style="margin:0;border-left:4px solid #dc3545">
    <h2 style="color:#dc3545">&#9888; Certificate Expiry Countdown</h2>
    <div class="section-body open">
        <div style="display:flex;gap:15px;margin-top:10px">
            <div style="text-align:center;padding:15px;border-radius:8px;min-width:120px;background:linear-gradient(135deg,#fff5f5,#ffe0e0);border:2px solid #dc3545;flex:1">
                <div style="font-size:.65em;color:#721c24;text-transform:uppercase;font-weight:bold">&#9888; FIRST TO EXPIRE</div>
                <div style="font-size:.85em;font-weight:bold;color:#dc3545;margin:3px 0">KEK CA 2011</div>
                <div id="daysKek" style="font-size:2.5em;font-weight:700;color:#dc3545;line-height:1">$daysToKek</div>
                <div style="font-size:.8em;color:#721c24">days (Jun 24, 2026)</div>
            </div>
            <div style="text-align:center;padding:15px;border-radius:8px;min-width:120px;background:linear-gradient(135deg,#fffef5,#fff3cd);border:2px solid #ffc107;flex:1">
                <div style="font-size:.65em;color:#856404;text-transform:uppercase;font-weight:bold">UEFI CA 2011</div>
                <div id="daysUefi" style="font-size:2.2em;font-weight:700;color:#856404;line-height:1;margin:5px 0">$daysToUefi</div>
                <div style="font-size:.8em;color:#856404">days (Jun 27, 2026)</div>
            </div>
            <div style="text-align:center;padding:15px;border-radius:8px;min-width:120px;background:linear-gradient(135deg,#f0f8ff,#d4edff);border:2px solid #0078d4;flex:1">
                <div style="font-size:.65em;color:#0078d4;text-transform:uppercase;font-weight:bold">Windows PCA</div>
                <div id="daysPca" style="font-size:2.2em;font-weight:700;color:#0078d4;line-height:1;margin:5px 0">$daysToPca</div>
                <div style="font-size:.8em;color:#0078d4">days (Oct 19, 2026)</div>
            </div>
        </div>
        <div style="margin-top:15px;padding:10px;background:#f8d7da;border-radius:8px;font-size:.85em;border-left:4px solid #dc3545">
            <strong>&#9888; CRITICAL:</strong> All devices must be updated before certificate expiry. Devices not updated by the deadline cannot apply future Security updates for Boot Manager and Secure Boot after expiry.
        </div>
    </div>
</div>
</div>

<!-- Charts -->
<div class="charts">
    <div class="chart-box"><h3>Deployment Status</h3><canvas id="deployChart" height="200"></canvas></div>
    <div class="chart-box"><h3>$mfrChartTitle</h3><canvas id="mfrChart" height="200"></canvas></div>
</div>

$(if ($historyData.Count -ge 1) {
"<!-- Historical Trend Chart -->
<div class='section'>
    <h2 onclick=`"toggle('d-trend')`">&#128200; Update Progress Over Time <a class='top-link' href='#'>&#8593; Top</a></h2>
    <div id='d-trend' class='section-body open'>
        <canvas id='trendChart' height='120'></canvas>
        <div style='font-size:.75em;color:#888;margin-top:5px'>Solid lines = actual data$(if ($historyData.Count -ge 2) { " | Dashed line = projected (exponential doubling: 2&#x2192;4&#x2192;8&#x2192;16... devices per wave)" } else { " | Run aggregation again tomorrow to see trend lines and projection" })</div>
    </div>
</div>"
})

<!-- CSV Downloads -->
<div class="section">
    <h2 onclick="toggle('dl-csv')">&#128229; Download Full Data (CSV for Excel) <a class="top-link" href="#">Top</a></h2>
    <div id="dl-csv" class="section-body open" style="display:flex;flex-wrap:wrap;gap:5px">
        <a href="SecureBoot_not_updated_$timestamp.csv" style="display:inline-block;background:#dc3545;color:#fff;padding:6px 14px;border-radius:5px;text-decoration:none;font-size:.8em">Not Updated ($($stNotUptodate.ToString("N0")))</a>
        <a href="SecureBoot_errors_$timestamp.csv" style="display:inline-block;background:#dc3545;color:#fff;padding:6px 14px;border-radius:5px;text-decoration:none;font-size:.8em">Errors ($($c.WithErrors.ToString("N0")))</a>
        <a href="SecureBoot_action_required_$timestamp.csv" style="display:inline-block;background:#fd7e14;color:#fff;padding:6px 14px;border-radius:5px;text-decoration:none;font-size:.8em">Action Required ($($c.ActionReq.ToString("N0")))</a>
        <a href="SecureBoot_known_issues_$timestamp.csv" style="display:inline-block;background:#dc3545;color:#fff;padding:6px 14px;border-radius:5px;text-decoration:none;font-size:.8em">Known Issues ($($c.WithKnownIssues.ToString("N0")))</a>
        <a href="SecureBoot_task_disabled_$timestamp.csv" style="display:inline-block;background:#dc3545;color:#fff;padding:6px 14px;border-radius:5px;text-decoration:none;font-size:.8em">Task Disabled ($($c.TaskDisabled.ToString("N0")))</a>
        <a href="SecureBoot_updated_devices_$timestamp.csv" style="display:inline-block;background:#28a745;color:#fff;padding:6px 14px;border-radius:5px;text-decoration:none;font-size:.8em">Updated ($($c.Updated.ToString("N0")))</a>
        <a href="SecureBoot_Summary_$timestamp.csv" style="display:inline-block;background:#6c757d;color:#fff;padding:6px 14px;border-radius:5px;text-decoration:none;font-size:.8em">Summary</a>
        <div style="width:100%;font-size:.75em;color:#888;margin-top:5px">CSV files open in Excel. Available when hosted on web server.</div>
    </div>
</div>

<!-- Manufacturer Breakdown -->
<div class="section">
    <h2 onclick="toggle('mfr')">By Manufacturer <a class="top-link" href="#">Top</a></h2>
    <div id="mfr" class="section-body open">
    <table><thead><tr><th>Manufacturer</th><th>Total</th><th>Updated</th><th>High Confidence</th><th>Action Required</th></tr></thead>
    <tbody>$mfrTableRows</tbody></table>
    </div>
</div>

<!-- Device Sections (first 200 inline + CSV download) -->
<div class="section" id="s-err">
    <h2 onclick="toggle('d-err')">&#128308; Devices with Errors ($($c.WithErrors.ToString("N0"))) <a class="top-link" href="#">&#8593; Top</a></h2>
    <div id="d-err" class="section-body">$tblErrors</div>
</div>
<div class="section" id="s-ki">
    <h2 onclick="toggle('d-ki')" style="color:#dc3545">&#128308; Known Issues ($($c.WithKnownIssues.ToString("N0"))) <a class="top-link" href="#">&#8593; Top</a></h2>
    <div id="d-ki" class="section-body">$tblKI</div>
</div>
<div class="section" id="s-kek">
    <h2 onclick="toggle('d-kek')">&#128992; Missing KEK - Event 1803 ($($c.WithMissingKEK.ToString("N0"))) <a class="top-link" href="#">&#8593; Top</a></h2>
    <div id="d-kek" class="section-body">$tblKEK</div>
</div>
<div class="section" id="s-ar">
    <h2 onclick="toggle('d-ar')" style="color:#fd7e14">&#128992; Action Required ($($c.ActionReq.ToString("N0"))) <a class="top-link" href="#">&#8593; Top</a></h2>
    <div id="d-ar" class="section-body">$tblActionReq</div>
</div>
<div class="section" id="s-uo">
    <h2 onclick="toggle('d-uo')" style="color:#17a2b8">&#128309; Under Observation ($($c.UnderObs.ToString("N0"))) <a class="top-link" href="#">&#8593; Top</a></h2>
    <div id="d-uo" class="section-body">$tblUnderObs</div>
</div>
<div class="section" id="s-nu">
    <h2 onclick="toggle('d-nu')" style="color:#dc3545">&#128308; Not Updated ($($stNotUptodate.ToString("N0"))) <a class="top-link" href="#">&#8593; Top</a></h2>
    <div id="d-nu" class="section-body">$tblNotUpd</div>
</div>
<div class="section" id="s-td">
    <h2 onclick="toggle('d-td')" style="color:#dc3545">&#128308; Task Disabled ($($c.TaskDisabled.ToString("N0"))) <a class="top-link" href="#">&#8593; Top</a></h2>
    <div id="d-td" class="section-body">$tblTaskDis</div>
</div>
<div class="section" id="s-tf">
    <h2 onclick="toggle('d-tf')" style="color:#dc3545">&#128308; Temporary Failures ($($c.TempFailures.ToString("N0"))) <a class="top-link" href="#">&#8593; Top</a></h2>
    <div id="d-tf" class="section-body">$tblTemp</div>
</div>
<div class="section" id="s-pf">
    <h2 onclick="toggle('d-pf')" style="color:#721c24">&#128308; Permanent Failures / Not Supported ($($c.PermFailures.ToString("N0"))) <a class="top-link" href="#">&#8593; Top</a></h2>
    <div id="d-pf" class="section-body">$tblPerm</div>
</div>
<div class="section" id="s-upd-pend">
    <h2 onclick="toggle('d-upd-pend')" style="color:#6f42c1">&#9203; Update Pending ($($c.UpdatePending.ToString("N0"))) - Policy/WinCS Applied, Awaiting Update <a class="top-link" href="#">&#8593; Top</a></h2>
    <div id="d-upd-pend" class="section-body"><p style="color:#666;margin-bottom:10px">Devices where AvailableUpdatesPolicy or WinCS key is applied but UEFICA2023Status is still NotStarted, InProgress, or null.</p>$tblUpdatePending</div>
</div>
<div class="section" id="s-rip">
    <h2 onclick="toggle('d-rip')" style="color:#17a2b8">&#128309; Rollout In Progress ($($c.RolloutInProgress.ToString("N0"))) <a class="top-link" href="#">&#8593; Top</a></h2>
    <div id="d-rip" class="section-body">$tblRolloutIP</div>
</div>
<div class="section" id="s-sboff">
    <h2 onclick="toggle('d-sboff')" style="color:#6c757d">&#9899; SecureBoot OFF ($($c.SBOff.ToString("N0"))) - Out of Scope <a class="top-link" href="#">&#8593; Top</a></h2>
    <div id="d-sboff" class="section-body">$tblSBOff</div>
</div>
<div class="section" id="s-upd">
    <h2 onclick="toggle('d-upd')" style="color:#28a745">&#128994; Updated Devices ($($c.Updated.ToString("N0"))) <a class="top-link" href="#">&#8593; Top</a></h2>
    <div id="d-upd" class="section-body">$tblUpdated</div>
</div>
<div class="section" id="s-nrb">
    <h2 onclick="toggle('d-nrb')" style="color:#ffc107">&#128260; Updated - Needs Reboot ($($c.NeedsReboot.ToString("N0"))) <a class="top-link" href="#">&#8593; Top</a></h2>
    <div id="d-nrb" class="section-body">$tblNeedsReboot</div>
</div>

<div class="footer">Secure Boot Certificate Rollout Dashboard | Generated $($stats.ReportGeneratedAt) | StreamingMode | Peak Memory: ${stPeakMemMB} MB</div>
</div><!-- /container -->

<script>
function toggle(id){var e=document.getElementById(id);e.classList.toggle('open')}
function openSection(id){var e=document.getElementById(id);if(e&&!e.classList.contains('open')){e.classList.add('open')}}
new Chart(document.getElementById('deployChart'),{type:'doughnut',data:{labels:['Updated','Update Pending','High Confidence','Under Observation','Action Required','Temp. Paused','Not Supported','SecureBoot OFF','With Errors'],datasets:[{data:[$($c.Updated),$($c.UpdatePending),$($c.HighConf),$($c.UnderObs),$($c.ActionReq),$($c.TempPaused),$($c.NotSupported),$($c.SBOff),$($c.WithErrors)],backgroundColor:['#28a745','#6f42c1','#20c997','#17a2b8','#fd7e14','#6c757d','#721c24','#adb5bd','#dc3545']}]},options:{responsive:true,plugins:{legend:{position:'right',labels:{font:{size:11}}}}}});
new Chart(document.getElementById('mfrChart'),{type:'bar',data:{labels:[$mfrLabels],datasets:[{label:'Updated',data:[$mfrUpdated],backgroundColor:'#28a745'},{label:'Update Pending',data:[$mfrUpdatePending],backgroundColor:'#6f42c1'},{label:'High Confidence',data:[$mfrHighConf],backgroundColor:'#20c997'},{label:'Under Observation',data:[$mfrUnderObs],backgroundColor:'#17a2b8'},{label:'Action Required',data:[$mfrActionReq],backgroundColor:'#fd7e14'},{label:'Temp. Paused',data:[$mfrTempPaused],backgroundColor:'#6c757d'},{label:'Not Supported',data:[$mfrNotSupported],backgroundColor:'#721c24'},{label:'SecureBoot OFF',data:[$mfrSBOff],backgroundColor:'#adb5bd'},{label:'With Errors',data:[$mfrWithErrors],backgroundColor:'#dc3545'}]},options:{responsive:true,scales:{x:{stacked:true},y:{stacked:true}},plugins:{legend:{position:'top'}}}});
// Historical Trend Chart
if (document.getElementById('trendChart')) {
var allLabels = [$allChartLabels];
var actualUpdated = [$trendUpdated];
var actualNotUpdated = [$trendNotUpdated];
var actualTotal = [$trendTotal];
var projData = [$projDataJS];
var projNotUpdData = [$projNotUpdJS];
var histLen = actualUpdated.length;
var projLen = projData.length;
var paddedUpdated = actualUpdated.concat(Array(projLen).fill(null));
var paddedNotUpdated = actualNotUpdated.concat(Array(projLen).fill(null));
var paddedTotal = actualTotal.concat(Array(projLen).fill(null));
var projLine = Array(histLen).fill(null);
var projNotUpdLine = Array(histLen).fill(null);
if (projLen > 0) { projLine[histLen-1] = actualUpdated[histLen-1]; projLine = projLine.concat(projData); projNotUpdLine[histLen-1] = actualNotUpdated[histLen-1]; projNotUpdLine = projNotUpdLine.concat(projNotUpdData); }
var datasets = [
    {label:'Updated',data:paddedUpdated,borderColor:'#28a745',backgroundColor:'rgba(40,167,69,0.1)',fill:true,tension:0.3,borderWidth:2},
    {label:'Not Updated',data:paddedNotUpdated,borderColor:'#dc3545',backgroundColor:'rgba(220,53,69,0.1)',fill:true,tension:0.3,borderWidth:2},
    {label:'Total',data:paddedTotal,borderColor:'#6c757d',borderDash:[5,5],fill:false,tension:0,pointRadius:0,borderWidth:1}
];
if (projLen > 0) {
    datasets.push({label:'Projected Updated (2x doubling)',data:projLine,borderColor:'#28a745',borderDash:[8,4],borderWidth:3,fill:false,tension:0.3,pointRadius:3,pointStyle:'triangle'});
    datasets.push({label:'Projected Not Updated',data:projNotUpdLine,borderColor:'#dc3545',borderDash:[8,4],borderWidth:3,fill:false,tension:0.3,pointRadius:3,pointStyle:'triangle'});
}
new Chart(document.getElementById('trendChart'),{type:'line',data:{labels:allLabels,datasets:datasets},options:{responsive:true,scales:{y:{beginAtZero:true,title:{display:true,text:'Devices'}},x:{title:{display:true,text:'Date'}}},plugins:{legend:{position:'top'},title:{display:true,text:'Secure Boot Update Progress Over Time'}}}});
}
// Dynamic countdown
(function(){var t=new Date(),k=new Date('2026-06-24'),u=new Date('2026-06-27'),p=new Date('2026-10-19');var dk=document.getElementById('daysKek'),du=document.getElementById('daysUefi'),dp=document.getElementById('daysPca');if(dk)dk.textContent=Math.max(0,Math.ceil((k-t)/864e5));if(du)du.textContent=Math.max(0,Math.ceil((u-t)/864e5));if(dp)dp.textContent=Math.max(0,Math.ceil((p-t)/864e5))})();
</script>
</body>
</html>
​​​​​​​"@
        [System.IO.File]::WriteAllText($htmlPath, $htmlContent, [System.Text.UTF8Encoding]::new($false))
        
        # Always keep a stable "Latest" copy so admins don't need to track timestamps
        $latestPath = Join-Path $OutputPath "SecureBoot_Dashboard_Latest.html"
        Copy-Item $htmlPath $latestPath -Force
        
        $stTotal = $streamSw.Elapsed.TotalSeconds
        
        # Save file manifest for incremental mode (quick no-change detection on next run)
        if ($IncrementalMode -or $StreamingMode) {
            $stManifestDir = Join-Path $OutputPath ".cache"
            if (-not (Test-Path $stManifestDir)) { New-Item -ItemType Directory -Path $stManifestDir -Force | Out-Null }
            $stManifestPath = Join-Path $stManifestDir "StreamingManifest.json"
            $stNewManifest = @{}
            Write-Host "Saving file manifest for incremental mode..." -ForegroundColor Gray
            foreach ($jf in $jsonFiles) {
                $stNewManifest[$jf.FullName.ToLowerInvariant()] = @{
                    LastWriteTimeUtc = $jf.LastWriteTimeUtc.ToString("o")
                    Size = $jf.Length
                }
            }
            Save-FileManifest -Manifest $stNewManifest -Path $stManifestPath
            Write-Host "   Saved manifest for $($stNewManifest.Count) files" -ForegroundColor DarkGray
        }
        
        # RETENTION CLEANUP
        # Orchestrator reusable folder (Aggregation_Current): keep only latest run (1)
        # Admin manual runs / other folders: keep last 7 runs
        # Summary CSVs are NEVER deleted — they're tiny (~1 KB) and are the backup source for trend history
        $outputLeaf = Split-Path $OutputPath -Leaf
        $retentionCount = if ($outputLeaf -eq 'Aggregation_Current') { 1 } else { 7 }
        # File prefixes safe to clean up (ephemeral per-run snapshots)
        $cleanupPrefixes = @(
            'SecureBoot_Dashboard_',
            'SecureBoot_action_required_',
            'SecureBoot_ByManufacturer_',
            'SecureBoot_ErrorCodes_',
            'SecureBoot_errors_',
            'SecureBoot_known_issues_',
            'SecureBoot_missing_kek_',
            'SecureBoot_needs_reboot_',
            'SecureBoot_not_updated_',
            'SecureBoot_secureboot_off_',
            'SecureBoot_task_disabled_',
            'SecureBoot_temp_failures_',
            'SecureBoot_perm_failures_',
            'SecureBoot_under_observation_',
            'SecureBoot_UniqueBuckets_',
            'SecureBoot_update_pending_',
            'SecureBoot_updated_devices_',
            'SecureBoot_rollout_inprogress_',
            'SecureBoot_NotUptodate_',
            'SecureBoot_Kusto_'
        )
        # Find all unique timestamps from cleanable files only
        $cleanableFiles = Get-ChildItem $OutputPath -File -EA SilentlyContinue |
            Where-Object { $f = $_.Name; ($cleanupPrefixes | Where-Object { $f.StartsWith($_) }).Count -gt 0 }
        $allTimestamps = @($cleanableFiles | ForEach-Object {
            if ($_.Name -match '(\d{8}-\d{6})') { $Matches[1] }
        } | Sort-Object -Unique -Descending)
        if ($allTimestamps.Count -gt $retentionCount) {
            $oldTimestamps = $allTimestamps | Select-Object -Skip $retentionCount
            $removedFiles = 0; $freedBytes = 0
            foreach ($oldTs in $oldTimestamps) {
                foreach ($prefix in $cleanupPrefixes) {
                    $oldFiles = Get-ChildItem $OutputPath -File -Filter "${prefix}${oldTs}*" -EA SilentlyContinue
                    foreach ($f in $oldFiles) {
                        $freedBytes += $f.Length
                        Remove-Item $f.FullName -Force -EA SilentlyContinue
                        $removedFiles++
                    }
                }
            }
            $freedMB = [math]::Round($freedBytes / 1MB, 1)
            Write-Host "Retention cleanup: removed $removedFiles files from $($oldTimestamps.Count) old runs, freed ${freedMB} MB (keeping last $retentionCount + all Summary/NotUptodate CSVs)" -ForegroundColor DarkGray
        }
        
        Write-Host "`n$("=" * 60)" -ForegroundColor Cyan
        Write-Host "STREAMING AGGREGATION COMPLETE" -ForegroundColor Green
        Write-Host ("=" * 60) -ForegroundColor Cyan
        Write-Host "  Total Devices:   $($c.Total.ToString("N0"))" -ForegroundColor White
        Write-Host "  NOT UPDATED:     $($stNotUptodate.ToString("N0")) ($($stats.PercentNotUptodate)%)" -ForegroundColor $(if ($stNotUptodate -gt 0) { "Yellow" } else { "Green" })
        Write-Host "  Updated:         $($c.Updated.ToString("N0")) ($($stats.PercentCertUpdated)%)" -ForegroundColor Green
        Write-Host "  With Errors:     $($c.WithErrors.ToString("N0"))" -ForegroundColor $(if ($c.WithErrors -gt 0) { "Red" } else { "Green" })
        Write-Host "  Peak Memory:     ${stPeakMemMB} MB" -ForegroundColor Cyan
        Write-Host "  Time:            $([math]::Round($stTotal/60,1)) min" -ForegroundColor White
        Write-Host "  Dashboard:       $htmlPath" -ForegroundColor White
        
        return [PSCustomObject]$stats
    }
    #endregion STREAMING MODE
} else {
    Write-Error "Input path not found: $InputPath"
    exit 1
}