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/push/lark.go

@@ -265,7 +265,7 @@ func (p *LarkPusher) ValidateConfig(cfg Config) error {
 }
 
 func larkSign(secret string, timestamp int64) (string, error) {
-	stringToSign := fmt.Sprintf("%v", timestamp) + "\n" + secret
+	stringToSign := strconv.FormatInt(timestamp, 10) + "\n" + secret
 	h := hmac.New(sha256.New, []byte(stringToSign))
 	_, err := h.Write(nil)
 	if err != nil {