v0.4.2

• Add Athena datasource provider (query, list catalogs/databases/tables, describe-table)
• Introduce shared SQL query package, refactoring ClickHouse onto it
• Synthetic Monitoring now syncs via a Grafana datasource proxy client
• Set X-Grafana-Caller-Id header on all datasource queries
• Refine output formatting (format and jq handling)
• Remove obsolete publish-technical-documentation workflows