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>

tests/setup/global-setup.ts

@@ -1,4 +1,11 @@
 import { beforeEach, afterEach, vi } from 'vitest';
+import { loadTestEnvironment, getTestConfig, getTestTimeout } from './test-env';
+
+// Load test environment configuration
+loadTestEnvironment();
+
+// Get test configuration
+const testConfig = getTestConfig();
 
 // Reset mocks between tests
 beforeEach(() => {
@@ -8,19 +15,40 @@ beforeEach(() => {
 // Clean up after each test
 afterEach(() => {
   vi.restoreAllMocks();
+  
+  // Perform cleanup if enabled
+  if (testConfig.cleanup.enabled) {
+    // Add cleanup logic here if needed
+  }
 });
 
-// Global test timeout
-vi.setConfig({ testTimeout: 10000 });
+// Global test timeout from configuration
+vi.setConfig({ testTimeout: getTestTimeout('global') });
 
-// Silence console during tests unless DEBUG=true
-if (process.env.DEBUG !== 'true') {
+// Configure console output based on test configuration
+if (!testConfig.logging.debug) {
   global.console = {
     ...console,
     log: vi.fn(),
     debug: vi.fn(),
     info: vi.fn(),
-    warn: vi.fn(),
-    error: vi.fn(),
+    warn: testConfig.logging.level === 'error' ? vi.fn() : console.warn,
+    error: console.error, // Always show errors
   };
-}
+}
+
+// Set up performance monitoring if enabled
+if (testConfig.performance) {
+  global.performance = global.performance || {
+    now: () => Date.now(),
+    mark: vi.fn(),
+    measure: vi.fn(),
+    getEntriesByName: vi.fn(() => []),
+    getEntriesByType: vi.fn(() => []),
+    clearMarks: vi.fn(),
+    clearMeasures: vi.fn(),
+  } as any;
+}
+
+// Export test configuration for use in tests
+export { testConfig, getTestTimeout, getTestConfig };