Returns the overall points-balance report for all account contacts as a CSV string wrapped in the canonical envelope. The CSV body has columns id,email,points balance -- the id column carries each contact's UUID. The report is generated at most once per 24 hours per account and served from cache on subsequent requests until the next 24h window. While generation is in progress, the endpoint returns HTTP 202 with a canonical envelope (success: true, message: "Report still processing."); subsequent requests during the same generation cycle continue to return 202 until the file is ready. On infrastructure error the endpoint returns HTTP 503 with a canonical error envelope. The linebreak parameter controls the linebreak character WITHIN the CSV string (it does NOT affect the JSON envelope itself).