Updated the PostgreSQL monitoring service to improve handling of `pg_stat_statements` availability. Introduced a new method to check if the extension is queryable and updated the response structure to include availability status and hints. Enhanced the documentation to clarify the requirements for enabling `pg_stat_statements`. Adjusted related components to reflect these changes, ensuring better user feedback in the monitoring interface.
Added PostgreSQL monitoring and maintenance capabilities to the API, including new endpoints for instance-level metrics, maintenance operations, and job scheduling. Updated the HTTP API to support PostgreSQL monitoring routes and integrated a background scheduler for metrics collection. Enhanced the CLI with database commands for maintenance tasks. Updated documentation to reflect these changes.