feat: add metrics, observability, test fixtures, and scaling playbook artifacts

scripts/loadtest/summarize-k6.ps1

@@ -0,0 +1,68 @@
+#!/usr/bin/env pwsh
+param(
+  [Parameter(Mandatory = $true)]
+  [string]$SummaryFile
+)
+
+$ErrorActionPreference = 'Stop'
+
+if (-not (Test-Path $SummaryFile)) {
+  throw "Summary file not found: $SummaryFile"
+}
+
+$summary = Get-Content -Raw -Path $SummaryFile | ConvertFrom-Json
+$metrics = $summary.metrics
+
+if (-not $metrics) {
+  throw 'Invalid k6 summary file: missing metrics object.'
+}
+
+$endpoints = @('overview', 'analytics', 'chat_log', 'users')
+
+function Get-MetricValue {
+  param(
+    [object]$Metric,
+    [string]$Key
+  )
+
+  if (-not $Metric) {
+    return $null
+  }
+  if (-not $Metric.values) {
+    return $null
+  }
+
+  $value = $Metric.values.$Key
+  if ($null -ne $value) {
+    return [double]$value
+  }
+  return $null
+}
+
+$globalDuration = Get-MetricValue -Metric $metrics.http_req_duration -Key 'p(95)'
+$globalFailRate = Get-MetricValue -Metric $metrics.http_req_failed -Key 'rate'
+
+Write-Output "k6 Summary: $SummaryFile"
+if ($null -ne $globalDuration) {
+  Write-Output ("Global p95 duration (ms): {0:N2}" -f $globalDuration)
+}
+if ($null -ne $globalFailRate) {
+  Write-Output ("Global failure rate: {0:P2}" -f $globalFailRate)
+}
+Write-Output ''
+
+$rows = foreach ($endpoint in $endpoints) {
+  $durationMetricName = "http_req_duration{endpoint:$endpoint}"
+  $failMetricName = "http_req_failed{endpoint:$endpoint}"
+
+  $durationP95 = Get-MetricValue -Metric $metrics.$durationMetricName -Key 'p(95)'
+  $failRate = Get-MetricValue -Metric $metrics.$failMetricName -Key 'rate'
+
+  [PSCustomObject]@{
+    Endpoint   = $endpoint
+    P95Ms      = if ($null -ne $durationP95) { [math]::Round($durationP95, 2) } else { $null }
+    FailurePct = if ($null -ne $failRate) { [math]::Round($failRate * 100, 4) } else { $null }
+  }
+}
+
+$rows | Format-Table -AutoSize | Out-String | Write-Output