Express MCP Handler

## Description <!-- Please include a summary of the change and which issue it addresses. --> ## Type of change - [ ] Bug fix (non-breaking change fixing an issue) - [ ] New feature (non-breaking change adding functionality) - [ ] Breaking change (fix or feature causing existing functionality to change) - [ ] Documentation update - [ ] Refactoring - [ ] Dependency update ## Checklist - [ ] I have performed a self-review of my own code - [ ] I have added tests that prove my fix is effective or that my feature works - [ ] I have updated the documentation accordingly - [ ] I have run `npm run lint` and fixed any issues - [ ] I have run `npm test` and all tests are passing - [ ] I have run `npm run build` and verified the output