Root virtual uv workspace (`packages/*`)

[ulises-jeremias]

Summary

Create root pyproject.toml as a virtual workspace (no root [project] publishable package) with members = ["packages/*"].

CNA mapping

CNA: root package.json workspaces: ["packages/*"].

Acceptance criteria

• Root pyproject.toml has [tool.uv.workspace] with packages/*
• uv sync succeeds on empty member stubs
• Documented in README (workspace layout diagram)

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

#2