#19 Add BigQuery connector/runtime

[Anonymous]

Originally created by: intraq-dev-ai

Connector gap

WrenAI supports BigQuery. IntraQ lists BigQuery in some UI/source-type paths, but the live SQL runner does not execute BigQuery queries.

Evidence

WrenAI docs list BigQuery as a supported OSS/cloud data source. IntraQ has BigQuery dialect helpers, but live execution types/runners only cover PostgreSQL, MySQL/MariaDB, SQL Server, Databricks, and ClickHouse.

Acceptance criteria

• Add a real BigQuery connector/runtime.
• Support service-account or workload-identity style credentials without committing secrets.
• Support dataset/table discovery, query preview, SQL Editor execution, Analyzer, and Dashboard Builder.
• Add tests for query limits, parameter handling, discovery, and connection errors.