feat: complete Phase 3.8 - test infrastructure and CI/CD enhancements

- Add test result artifacts storage with multiple formats (JUnit, JSON, HTML)
- Configure GitHub Actions to upload and preserve test outputs
- Add PR comment integration with test summaries
- Create benchmark comparison workflow for PR performance tracking
- Add detailed test report generation scripts
- Configure artifact retention policies (30 days for tests, 90 for combined)
- Set up test metadata collection for better debugging

This completes all remaining test infrastructure tasks and provides
comprehensive visibility into test results across CI/CD pipeline.

scripts/generate-test-summary.js

@@ -0,0 +1,167 @@
+#!/usr/bin/env node
+import { readFileSync, existsSync } from 'fs';
+import { resolve } from 'path';
+
+/**
+ * Generate a markdown summary of test results for PR comments
+ */
+function generateTestSummary() {
+  const results = {
+    tests: null,
+    coverage: null,
+    benchmarks: null,
+    timestamp: new Date().toISOString()
+  };
+
+  // Read test results
+  const testResultPath = resolve(process.cwd(), 'test-results/results.json');
+  if (existsSync(testResultPath)) {
+    try {
+      const testData = JSON.parse(readFileSync(testResultPath, 'utf-8'));
+      const totalTests = testData.numTotalTests || 0;
+      const passedTests = testData.numPassedTests || 0;
+      const failedTests = testData.numFailedTests || 0;
+      const skippedTests = testData.numSkippedTests || 0;
+      const duration = testData.duration || 0;
+
+      results.tests = {
+        total: totalTests,
+        passed: passedTests,
+        failed: failedTests,
+        skipped: skippedTests,
+        duration: duration,
+        success: failedTests === 0
+      };
+    } catch (error) {
+      console.error('Error reading test results:', error);
+    }
+  }
+
+  // Read coverage results
+  const coveragePath = resolve(process.cwd(), 'coverage/coverage-summary.json');
+  if (existsSync(coveragePath)) {
+    try {
+      const coverageData = JSON.parse(readFileSync(coveragePath, 'utf-8'));
+      const total = coverageData.total;
+      
+      results.coverage = {
+        lines: total.lines.pct,
+        statements: total.statements.pct,
+        functions: total.functions.pct,
+        branches: total.branches.pct
+      };
+    } catch (error) {
+      console.error('Error reading coverage results:', error);
+    }
+  }
+
+  // Read benchmark results
+  const benchmarkPath = resolve(process.cwd(), 'benchmark-results.json');
+  if (existsSync(benchmarkPath)) {
+    try {
+      const benchmarkData = JSON.parse(readFileSync(benchmarkPath, 'utf-8'));
+      const benchmarks = [];
+      
+      for (const file of benchmarkData.files || []) {
+        for (const group of file.groups || []) {
+          for (const benchmark of group.benchmarks || []) {
+            benchmarks.push({
+              name: `${group.name} - ${benchmark.name}`,
+              mean: benchmark.result.mean,
+              ops: benchmark.result.hz
+            });
+          }
+        }
+      }
+      
+      results.benchmarks = benchmarks;
+    } catch (error) {
+      console.error('Error reading benchmark results:', error);
+    }
+  }
+
+  // Generate markdown summary
+  let summary = '## Test Results Summary\n\n';
+  
+  // Test results
+  if (results.tests) {
+    const { total, passed, failed, skipped, duration, success } = results.tests;
+    const emoji = success ? '✅' : '❌';
+    const status = success ? 'PASSED' : 'FAILED';
+    
+    summary += `### ${emoji} Tests ${status}\n\n`;
+    summary += `| Metric | Value |\n`;
+    summary += `|--------|-------|\n`;
+    summary += `| Total Tests | ${total} |\n`;
+    summary += `| Passed | ${passed} |\n`;
+    summary += `| Failed | ${failed} |\n`;
+    summary += `| Skipped | ${skipped} |\n`;
+    summary += `| Duration | ${(duration / 1000).toFixed(2)}s |\n\n`;
+  }
+
+  // Coverage results
+  if (results.coverage) {
+    const { lines, statements, functions, branches } = results.coverage;
+    const avgCoverage = (lines + statements + functions + branches) / 4;
+    const emoji = avgCoverage >= 80 ? '✅' : avgCoverage >= 60 ? '⚠️' : '❌';
+    
+    summary += `### ${emoji} Coverage Report\n\n`;
+    summary += `| Type | Coverage |\n`;
+    summary += `|------|----------|\n`;
+    summary += `| Lines | ${lines.toFixed(2)}% |\n`;
+    summary += `| Statements | ${statements.toFixed(2)}% |\n`;
+    summary += `| Functions | ${functions.toFixed(2)}% |\n`;
+    summary += `| Branches | ${branches.toFixed(2)}% |\n`;
+    summary += `| **Average** | **${avgCoverage.toFixed(2)}%** |\n\n`;
+  }
+
+  // Benchmark results
+  if (results.benchmarks && results.benchmarks.length > 0) {
+    summary += `### ⚡ Benchmark Results\n\n`;
+    summary += `| Benchmark | Ops/sec | Mean (ms) |\n`;
+    summary += `|-----------|---------|------------|\n`;
+    
+    for (const bench of results.benchmarks.slice(0, 10)) { // Show top 10
+      const opsFormatted = bench.ops.toLocaleString('en-US', { maximumFractionDigits: 0 });
+      const meanFormatted = (bench.mean * 1000).toFixed(3);
+      summary += `| ${bench.name} | ${opsFormatted} | ${meanFormatted} |\n`;
+    }
+    
+    if (results.benchmarks.length > 10) {
+      summary += `\n*...and ${results.benchmarks.length - 10} more benchmarks*\n`;
+    }
+    summary += '\n';
+  }
+
+  // Links to artifacts
+  const runId = process.env.GITHUB_RUN_ID;
+  const runNumber = process.env.GITHUB_RUN_NUMBER;
+  const sha = process.env.GITHUB_SHA;
+  
+  if (runId) {
+    summary += `### 📊 Artifacts\n\n`;
+    summary += `- 📄 [Test Results](https://github.com/${process.env.GITHUB_REPOSITORY}/actions/runs/${runId})\n`;
+    summary += `- 📊 [Coverage Report](https://github.com/${process.env.GITHUB_REPOSITORY}/actions/runs/${runId})\n`;
+    summary += `- ⚡ [Benchmark Results](https://github.com/${process.env.GITHUB_REPOSITORY}/actions/runs/${runId})\n\n`;
+  }
+
+  // Metadata
+  summary += `---\n`;
+  summary += `*Generated at ${new Date().toUTCString()}*\n`;
+  if (sha) {
+    summary += `*Commit: ${sha.substring(0, 7)}*\n`;
+  }
+  if (runNumber) {
+    summary += `*Run: #${runNumber}*\n`;
+  }
+
+  return summary;
+}
+
+// Generate and output summary
+const summary = generateTestSummary();
+console.log(summary);
+
+// Also write to file for artifact
+import { writeFileSync } from 'fs';
+writeFileSync('test-summary.md', summary);