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/factories/property-definition-factory.ts

@@ -0,0 +1,28 @@
+import { Factory } from 'fishery';
+import { faker } from '@faker-js/faker';
+
+interface PropertyDefinition {
+  name: string;
+  displayName: string;
+  type: string;
+  default?: any;
+  required?: boolean;
+  description?: string;
+  options?: any[];
+}
+
+export const PropertyDefinitionFactory = Factory.define<PropertyDefinition>(() => ({
+  name: faker.helpers.camelCase(faker.word.noun() + ' ' + faker.word.adjective()),
+  displayName: faker.helpers.arrayElement(['URL', 'Method', 'Headers', 'Body', 'Authentication']),
+  type: faker.helpers.arrayElement(['string', 'number', 'boolean', 'options', 'json']),
+  default: faker.datatype.boolean() ? faker.word.sample() : undefined,
+  required: faker.datatype.boolean(),
+  description: faker.lorem.sentence(),
+  options: faker.datatype.boolean() ? [
+    {
+      name: faker.word.noun(),
+      value: faker.word.noun(),
+      description: faker.lorem.sentence()
+    }
+  ] : undefined
+}));