Set up a vignette catalog

Bring a freshly cloned catalog to a running marimo kernel, then hand off to composition.

Steps

1. Read the catalog manifest. Read catalog.toml at the repo root for first_notebook, auth (any required env var), and the catalog name. If there is no catalog.toml, fall back to the lowest-numbered notebook in notebooks/ and check README.md for auth.

2. Check the runtime. Confirm uv is installed (uv --version); if missing, install it:

   curl -LsSf https://astral.sh/uv/install.sh | sh
   

3. Install the marimo-pair skill for the user's agent (it is how you drive a live kernel):