redash-query-runner-extensibility-hook

Redash’s BaseQueryRunner / BaseSQLQueryRunner framework supports ~70 bundled drivers activatable via REDASH_ENABLED_QUERY_RUNNERS env var without code rebuilds. New connectors register at module level via register(cls) populating a query_runners dict. This is Vantage’s extensibility point for future data sources beyond Snowflake — framework stays dormant-activatable per Law 10.