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>

vitest.config.ts

@@ -6,16 +6,43 @@ export default defineConfig({
     globals: true,
     environment: 'node',
     setupFiles: ['./tests/setup/global-setup.ts'],
+    // Load environment variables from .env.test
+    env: {
+      NODE_ENV: 'test'
+    },
+    // Test execution settings
+    pool: 'threads',
+    poolOptions: {
+      threads: {
+        singleThread: process.env.TEST_PARALLEL !== 'true',
+        maxThreads: parseInt(process.env.TEST_MAX_WORKERS || '4', 10),
+        minThreads: 1
+      }
+    },
+    // Retry configuration
+    retry: parseInt(process.env.TEST_RETRY_ATTEMPTS || '2', 10),
+    // Test reporter
+    reporters: process.env.CI ? ['default', 'json', 'junit'] : ['default'],
+    outputFile: {
+      json: './test-results/results.json',
+      junit: './test-results/junit.xml'
+    },
     coverage: {
       provider: 'v8',
-      reporter: ['text', 'json', 'html', 'lcov'],
+      enabled: process.env.FEATURE_TEST_COVERAGE !== 'false',
+      reporter: (process.env.COVERAGE_REPORTER || 'lcov,html,text-summary').split(','),
+      reportsDirectory: process.env.COVERAGE_DIR || './coverage',
       exclude: [
         'node_modules/',
         'tests/',
         '**/*.d.ts',
         '**/*.test.ts',
+        '**/*.spec.ts',
         'scripts/',
-        'dist/'
+        'dist/',
+        '**/test-*.ts',
+        '**/mock-*.ts',
+        '**/__mocks__/**'
       ],
       thresholds: {
         lines: 80,
@@ -23,12 +50,24 @@ export default defineConfig({
         branches: 75,
         statements: 80
       }
-    }
+    },
+    // Test isolation
+    isolate: true,
+    // File watch settings
+    watchExclude: ['**/node_modules/**', '**/dist/**', '**/.git/**']
   },
   resolve: {
     alias: {
       '@': path.resolve(__dirname, './src'),
       '@tests': path.resolve(__dirname, './tests')
     }
+  },
+  // TypeScript configuration
+  esbuild: {
+    target: 'node18'
+  },
+  // Define global constants
+  define: {
+    'process.env.TEST_ENVIRONMENT': JSON.stringify('true')
   }
 });