Separate the registry setup step from the CLI usage command,
making it clearer that the `@zen` registry only needs to be
configured once via `npm config set` before running `npx @zen/start`.
Replace step-numbered logging with minimal ANSI-styled output
using `step`, `done`, and `fail` helpers. Consolidate redundant
README and package.json updates into a single block, remove
verbose inline comments, and simplify file creation by eliminating
unnecessary variable assignments.