Function execute_plan 

pub async fn execute_plan(
    client: &Client,
    plan: &PostgresPolicyPlan,
    pool: &PgPool,
    sql_context: &SqlContext,
    changes: &[Change],
) -> Result<(), ReconcileError>

Execute an approved plan against the database.

Reads SQL from inline status or the referenced ConfigMap, executes it in a transaction, and updates the plan status to Applied or Failed.