fix(config): remove invalid npmrc min-release-age that breaks npx

The project .npmrc contained min-release-age=7d which is a pnpm-specific
setting not recognised by npm. npm 11 interprets this as before=null,
causing 'Invalid time value' errors on every npx invocation. This broke
all CLI integration tests that use npx tsx to run the CLI.

The minimum release age is already enforced globally via pnpm config
(minimum-release-age=10080 in ~/Library/Preferences/pnpm/rc) and npm
global config (min-release-age=7 in ~/.npmrc), so the project-level
setting was redundant as well as invalid.

Author: Mearman