When running in pnpm projects, the .npmrc configuration propagates as
NPM_CONFIG_* environment variables to child processes. This can cause
MCP servers to fail due to registry/proxy conflicts or case sensitivity
issues between uppercase and lowercase variants.
This fix adds a createCleanMcpEnvironment function that filters out:
- NPM_CONFIG_* and npm_config_* (npm/pnpm config)
- YARN_* (yarn config)
- PNPM_* (pnpm config)
- NO_UPDATE_NOTIFIER
Fixes#456
Co-authored-by: sisyphus-dev-ai <sisyphus-dev-ai@users.noreply.github.com>