全局重命名：kefu_sys / kefu-sys 改为 kefu_cloud / kefu-cloud

- Go module 与全部 import 路径
- 数据库默认库名、Docker 服务/卷命名与部署文档

server/internal/handler/ops_metrics.go

@@ -10,11 +10,11 @@ import (
 	"github.com/shirou/gopsutil/v4/cpu"
 	"github.com/shirou/gopsutil/v4/disk"
 	"github.com/shirou/gopsutil/v4/mem"
-	"kefu-sys/server/internal/metrics"
-	"kefu-sys/server/internal/middleware"
-	"kefu-sys/server/internal/model"
-	"kefu-sys/server/internal/storage"
-	"kefu-sys/server/internal/ws"
+	"kefu-cloud/server/internal/metrics"
+	"kefu-cloud/server/internal/middleware"
+	"kefu-cloud/server/internal/model"
+	"kefu-cloud/server/internal/storage"
+	"kefu-cloud/server/internal/ws"
 )
 
 // OpsMetrics 平台运维实时指标（当前 API 实例视角）。