This skill should be used when the user says "ensure config", "check arness config", "arn-code-ensure-config", "verify arness setup", or wants to verify that Arness Code configuration is present for the current project. This skill is primarily consumed as a reference by entry-point skills (arn-planning, arn-implementing, arn-shipping, arn-reviewing-pr, arn-assessing, arn-code-feature-spec, arn-code-bug-spec, arn-code-swift, arn-code-standard) which read the ensure-config reference as Step 0 before proceeding with their workflow.