v0.2.0-rc.6: audience reference

One activity stream, every reported number reproducible. Synthetic reference implementation for AI businesses that meter tokens and seats.

• Runs locally on DuckDB, no credentials: pip install -e ".[dev]" && tl demo
• Four-task open-book agent challenge (AGENTS.md) with a deterministic grader
• Same definitions and receipts re-performed on BigQuery against an independent dbt baseline; measured trade-off and the failed tenfold hypothesis are both retained in docs/evidence.md
• Hosted Codespaces reproduction and independent QA recorded under docs/verification/

Approved bytes: 84ac935 (merge 0843b56). Comparative agent accuracy and incremental cloud performance remain unmeasured.