feat: add comprehensive performance benchmark tracking system

- Create benchmark test suites for critical operations:
  - Node loading performance
  - Database query performance
  - Search operations performance
  - Validation performance
  - MCP tool execution performance

- Add GitHub Actions workflow for benchmark tracking:
  - Runs on push to main and PRs
  - Uses github-action-benchmark for historical tracking
  - Comments on PRs with performance results
  - Alerts on >10% performance regressions
  - Stores results in GitHub Pages

- Create benchmark infrastructure:
  - Custom Vitest benchmark configuration
  - JSON reporter for CI results
  - Result formatter for github-action-benchmark
  - Performance threshold documentation

- Add supporting utilities:
  - SQLiteStorageService for benchmark database setup
  - MCPEngine wrapper for testing MCP tools
  - Test factories for generating benchmark data
  - Enhanced NodeRepository with benchmark methods

- Document benchmark system:
  - Comprehensive benchmark guide in docs/BENCHMARKS.md
  - Performance thresholds in .github/BENCHMARK_THRESHOLDS.md
  - README for benchmarks directory
  - Integration with existing test suite

The benchmark system will help monitor performance over time and catch regressions before they reach production.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

scripts/format-benchmark-results.js

@@ -0,0 +1,86 @@
+#!/usr/bin/env node
+
+const fs = require('fs');
+const path = require('path');
+
+/**
+ * Formats Vitest benchmark results for github-action-benchmark
+ * Converts from Vitest format to the expected format
+ */
+function formatBenchmarkResults() {
+  const resultsPath = path.join(process.cwd(), 'benchmark-results.json');
+  
+  if (!fs.existsSync(resultsPath)) {
+    console.error('benchmark-results.json not found');
+    process.exit(1);
+  }
+
+  const vitestResults = JSON.parse(fs.readFileSync(resultsPath, 'utf8'));
+  
+  // Convert to github-action-benchmark format
+  const formattedResults = [];
+
+  // Vitest benchmark JSON reporter format
+  if (vitestResults.files) {
+    for (const file of vitestResults.files) {
+      const suiteName = path.basename(file.filepath, '.bench.ts');
+      
+      // Process each suite in the file
+      if (file.groups) {
+        for (const group of file.groups) {
+          for (const benchmark of group.benchmarks || []) {
+            if (benchmark.result) {
+              formattedResults.push({
+                name: `${suiteName} - ${benchmark.name}`,
+                unit: 'ms',
+                value: benchmark.result.mean || 0,
+                range: (benchmark.result.max - benchmark.result.min) || 0,
+                extra: `${benchmark.result.hz?.toFixed(0) || 0} ops/sec`
+              });
+            }
+          }
+        }
+      }
+    }
+  } else if (Array.isArray(vitestResults)) {
+    // Alternative format handling
+    for (const result of vitestResults) {
+      if (result.name && result.result) {
+        formattedResults.push({
+          name: result.name,
+          unit: 'ms',
+          value: result.result.mean || 0,
+          range: (result.result.max - result.result.min) || 0,
+          extra: `${result.result.hz?.toFixed(0) || 0} ops/sec`
+        });
+      }
+    }
+  }
+
+  // Write formatted results
+  const outputPath = path.join(process.cwd(), 'benchmark-results-formatted.json');
+  fs.writeFileSync(outputPath, JSON.stringify(formattedResults, null, 2));
+  
+  // Also create a summary for PR comments
+  const summary = {
+    timestamp: new Date().toISOString(),
+    benchmarks: formattedResults.map(b => ({
+      name: b.name,
+      time: `${b.value.toFixed(3)}ms`,
+      opsPerSec: b.extra,
+      range: `±${(b.range / 2).toFixed(3)}ms`
+    }))
+  };
+  
+  fs.writeFileSync(
+    path.join(process.cwd(), 'benchmark-summary.json'),
+    JSON.stringify(summary, null, 2)
+  );
+
+  console.log(`Formatted ${formattedResults.length} benchmark results`);
+}
+
+// Run if called directly
+if (require.main === module) {
+  formatBenchmarkResults();
+}