v2.4.0

dbt integration

• New installable dbt package: integrations/dbt-statguardian/ — captures dbt run/test results via on-run-start/on-run-end hooks, exposes a generic statguardian.contract_passed test and a statguardian.contract_recently_validated freshness test, plus reporting models.
• New statguardian dbt validate CLI subcommand — runs .sg contracts against your dbt models' real warehouse tables (Postgres, Redshift, Snowflake, BigQuery, DuckDB) and writes results back for the dbt test to pick up.
• Docs: docs/DBT_INTEGRATION.md, runnable end-to-end example in integrations/dbt-statguardian/integration_tests/ (DuckDB).
• Install with pip install "statguardian[dbt]".

Fixes

• execute_sql(), execute_spark(), and execute_cloud() were broken for everyone — they imported from a nonexistent statguardian._statguard module (typo) instead of the real compiled statguardian._statguardian. Fixed.