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}

internal/apps/openflare/agent/waf_ip_group.go

@@ -46,7 +46,7 @@ func ChangedWAFIPGroupsForAgent(ctx context.Context, ids []uint, checksums map[s
 	}
 	changed := make([]WAFIPGroup, 0, len(groups))
 	for _, group := range groups {
-		if strings.TrimSpace(checksums[fmt.Sprintf("%d", group.ID)]) == group.Checksum {
+		if strings.TrimSpace(checksums[strconv.FormatUint(uint64(group.ID), 10)]) == group.Checksum {
 			continue
 		}
 		changed = append(changed, group)