Rich console UX + hero asset placeholders

[ulises-jeremias]

Summary

Polish CLI output; placeholder branding assets.

CNA mapping

CNA: picocolors + assets/hero.svg + README badges.

Acceptance criteria

• Consistent success/error styling
• Placeholder hero SVG under package assets
• README install section for uvx / pipx

Blocked by

none

Blocks

none

Reference

Parity matrix (workspace): knowledge/create-python-app-parity-matrix.md
Reference repo: https://github.com/Create-Node-App/create-node-app

Parent epic

#5