perfsprint 18→0：strconv.Itoa/FormatInt/FormatUint/FormatBool 替代 fmt.Sprintf、无动词 fmt.Errorf→errors.New、纯字符串拼接。全部语义等价（已核对 diff）。修正 fixer 遗留的 import 问题（引入 goimports 统一整理）。

Result: {"status":"keep","total_issues":56,"golint_canonicalheader":8,"golint_errname":1,"golint_errorlint":12,"golint_forcetypeassert":3,"golint_gosec":0,"golint_intrange":3,"golint_modernize":5,"golint_nilnil":3,"golint_perfsprint":0,"golint_prealloc":3,"golint_recvcheck":7,"golint_usestdlibvars":3,"golint_wastedassign":7,"golint_total":55,"eslint_problems":1,"eslint_errors":0,"eslint_warnings":1,"tsc_errors":0,"measure_s":47}

pkg/util/format.go

@@ -29,13 +29,13 @@ func Bytes2Size(num int64) string {
 		numStr = fmt.Sprintf("%.2f", float64(num)/float64(sizeGB))
 		unit = "GB"
 	case num/int64(sizeMB) >= 1:
-		numStr = fmt.Sprintf("%d", int(float64(num)/float64(sizeMB)))
+		numStr = strconv.Itoa(int(float64(num) / float64(sizeMB)))
 		unit = "MB"
 	case num/int64(sizeKB) >= 1:
-		numStr = fmt.Sprintf("%d", int(float64(num)/float64(sizeKB)))
+		numStr = strconv.Itoa(int(float64(num) / float64(sizeKB)))
 		unit = "KB"
 	default:
-		numStr = fmt.Sprintf("%d", num)
+		numStr = strconv.FormatInt(num, 10)
 	}
 	return numStr + " " + unit
 }