This skill should be used when the user says "ensure config", "check arn spark config", "arn-spark-ensure-config", "verify arn spark setup", "configure spark", "setup arness spark", "spark config", or wants to verify that Arness Spark configuration is present for the current project. This skill is primarily consumed as a reference by entry-point skills (arn-brainstorming, arn-spark-discover, arn-spark-arch-vision) which read the ensure-config reference as Step 0 before proceeding with their workflow.