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>