chore: bump version to 2.7.23 and update documentation

- Bump version from 2.7.22 to 2.7.23 in package.json
- Update version badge in README.md
- Add tests badge showing 1,182 passing tests
- Add comprehensive CHANGELOG entry for v2.7.23 documenting:
  - Complete testing infrastructure implementation
  - 933 unit tests and 249 integration tests
  - All CI test failures fixed
  - Test architecture enhancements
  - Documentation updates
  - Development artifact cleanup

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

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

README.md

@@ -2,9 +2,10 @@
 
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
 [![GitHub stars](https://img.shields.io/github/stars/czlonkowski/n8n-mcp?style=social)](https://github.com/czlonkowski/n8n-mcp)
-[![Version](https://img.shields.io/badge/version-2.7.22-blue.svg)](https://github.com/czlonkowski/n8n-mcp)
+[![Version](https://img.shields.io/badge/version-2.7.23-blue.svg)](https://github.com/czlonkowski/n8n-mcp)
 [![npm version](https://img.shields.io/npm/v/n8n-mcp.svg)](https://www.npmjs.com/package/n8n-mcp)
 [![codecov](https://codecov.io/gh/czlonkowski/n8n-mcp/graph/badge.svg?token=YOUR_TOKEN)](https://codecov.io/gh/czlonkowski/n8n-mcp)
+[![Tests](https://img.shields.io/badge/tests-1182%20passing-brightgreen.svg)](https://github.com/czlonkowski/n8n-mcp/actions)
 [![n8n version](https://img.shields.io/badge/n8n-v1.103.2-orange.svg)](https://github.com/n8n-io/n8n)
 [![Docker](https://img.shields.io/badge/docker-ghcr.io%2Fczlonkowski%2Fn8n--mcp-green.svg)](https://github.com/czlonkowski/n8n-mcp/pkgs/container/n8n-mcp)
 [![Deploy on Railway](https://railway.com/button.svg)](https://railway.com/deploy/VY6UOG?referralCode=n8n-mcp)