modernize 37→5（-32）：interface{}→any、内置 max/min、slices/maps 辅助、strings.Cut/SplitSeq、strings.Builder（修复 mail.go O(n²) 拼接）。逐 hunk 核对语义等价；omitzero 冲突修复被自动跳过（wire 格式不变）；手动清 4 处遗留 sort import + 2 处 QF1012。

Result: {"status":"keep","total_issues":74,"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":18,"golint_prealloc":3,"golint_recvcheck":7,"golint_usestdlibvars":3,"golint_wastedassign":7,"golint_total":73,"eslint_problems":1,"eslint_errors":0,"eslint_warnings":1,"tsc_errors":0,"measure_s":38}

internal/apps/openflare/tls/obtain.go

@@ -123,7 +123,7 @@ func splitAcmeDomains(primaryDomain, otherDomains string) []string {
 	if !strings.Contains(otherDomains, "\n") && strings.Contains(otherDomains, ",") {
 		separator = ","
 	}
-	for _, domain := range strings.Split(otherDomains, separator) {
+	for domain := range strings.SplitSeq(otherDomains, separator) {
 		domain = strings.TrimSpace(domain)
 		if domain != "" {
 			domains = append(domains, domain)