Switch uv-venv to uv project env in example-basic

This way users could have their own package of various utilities. On the other hand, that does make it easier to forget inputs.

Start by locating the example-basic configuration that currently uses uv-venv and identify how the project environment is defined. Compare the current setup with the requested uv project environment, including how utility packages and inputs are represented. Done means the example uses the new environment approach without losing required inputs.

索引モデルが issue の本文から書いたものです。