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>

.github/workflows/test.yml

@@ -15,6 +15,20 @@ jobs:
           node-version: 20
           cache: 'npm'
       - run: npm ci
-      - run: npm test  # Now runs Vitest with all 68 tests passing
+      - run: npm run test:coverage  # Run tests with coverage
+      - name: Upload coverage to Codecov
+        uses: codecov/codecov-action@v4
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          files: ./coverage/lcov.info
+          flags: unittests
+          name: codecov-umbrella
+          fail_ci_if_error: true
+          verbose: true
       - run: npm run lint
-      - run: npm run typecheck || true  # Allow to fail initially
+      - run: npm run typecheck || true  # Allow to fail initially
+      
+      # Run benchmarks as part of CI (without performance regression checks)
+      - name: Run benchmarks (smoke test)
+        run: npm run benchmark -- --run tests/benchmarks/sample.bench.ts
+        continue-on-error: true