fix(report): preserve timing section in merged SUMMARY.md

merge-parity-reports.js constructs the merged SUMMARY.md from scratch
but was not extracting or including the Validation Timing section from
per-IG reports. Add timing row extraction and aggregation so the timing
table survives into the merged output and gets parsed by generate-badges.js.

Author: quotentiroler

scripts/merge-parity-reports.js

@@ -59,6 +59,7 @@ let validatorName = 'Firely';
 let tableHeader = '';
 let tableHeaderSep = '';
 let metricDefs = '';
+const timingRows = [];
 
 for (const { dirName, pkgName } of pkgDirs) {
   const pkgDir = path.join(inputDir, dirName);
@@ -157,6 +158,14 @@ for (const { dirName, pkgName } of pkgDirs) {
     }
   }
 
+  // Extract timing table rows
+  const timingRe = /## Validation Timing[\s\S]*?\|[-| ]+\|\n([\s\S]*?)(?=\n(?:## |$))/;
+  const timingMatch = summary.match(timingRe);
+  if (timingMatch) {
+    const rows = timingMatch[1].trim().split('\n').filter(l => l.startsWith('|'));
+    timingRows.push(...rows);
+  }
+
   // Copy all report files (DETAIL.md, *.json, *.txt) to output
   const files = fs.readdirSync(pkgDir);
   for (const file of files) {
@@ -218,6 +227,30 @@ for (const [metric, { passed, total }] of mergedStats) {
   }
 }
 
+// Build timing section from collected per-package rows
+const timingSection = (() => {
+  if (timingRows.length === 0) return '';
+  // Parse rows to compute totals
+  let totalResources = 0;
+  let totalS = 0;
+  for (const row of timingRows) {
+    const m = row.match(/\|\s*[^|]+\|\s*(\d+)\s*\|\s*([\d.]+)\s*\|/);
+    if (m) {
+      totalResources += parseInt(m[1]);
+      totalS += parseFloat(m[2]);
+    }
+  }
+  return `
+## Validation Timing
+
+Internal \`validate()\` performance across ${totalResources} resources (${totalS.toFixed(2)}s total).
+
+| Package | Resources | Total (s) | Avg (ms) | Median (ms) | p95 (ms) |
+|---------|-----------|-----------|----------|-------------|----------|
+${timingRows.join('\n')}
+`;
+})();
+
 const summary = `# Pipeline Parity Summary (FHIR ${fhirRelease})
 Generated: ${new Date().toISOString()}
 
@@ -242,7 +275,7 @@ ${overallRows.join('\n')}
 ### Metric Definitions
 ${metricDefs}
 ${validatorBugsSection}
-${fieldExclusionsSection}
+${fieldExclusionsSection}${timingSection}
 ## Environment
 - FHIR_RELEASE: ${fhirRelease}
 - PIPELINE_PACKAGES: ${pkgDirs.map(d => d.pkgName).join(', ')}