Check Close/CloseNow errors, drop unused helpers and dead constants, lowercase ST1005 error strings, and stop discarding unwrap status as an unused assignment so CI golangci-lint passes.
从 personal-dev 取优并接线到 feat/grok-complete-integration： - 调度阈值：grok_sched_* 写入、ApplyAccountSchedulingThreshold、 account_scheduling_thresholds 设置与 Settings UI、网关过滤 - 配额头：x-rate-limit 别名、相对秒 reset、tier/entitlement 扩展 - 批量 usage：GetUsageBatch + POST /usage/batch + AccountsView 合并加载 - CLI 身份：xai.cli_identity 统一 pin/UA；service 层 applyGrokCLIHeaders 与 transport 最终改写对齐；media eligibility 模块落地 - UsageCell：月度 cents→USD 与 30d 进度条展示 保留既有 failure taxonomy / sticky / free recovery 等 HEAD cools。
IanShaw027