0.4.2

• Breaking: the flattened answers exported by the experiment notebook now carry code, model_name, provider_name and profile_name ahead of the parsed values, so a row can be traced back to the combination that produced it. transform.flattened_only() adds them unconditionally; stats.value_counts_summary() leaves them out of the answer profile.
• Both analysis notebooks split their setup cell in three — folders, imports, then DB_FILE / SEARCHES alone with the prints, so the value a reader actually changes is easy to find.
• Add stats.answers_by_model() and plots.plot_answers_by_model(): one answer column crosstabbed against provider and model, as a table and as a chart. Both are wired into analyse_experiment.ipynb — re-run analysis init --rewrite to pick them up.