fix: 修复3个实测输出问题

1. 静默模式NDJSON banner截断至200字符
   Redis INFO响应~5KB导致JSONL单行过长，截断后加...后缀

2. CSV漏洞Type列补全
   ResultTypeVuln的fillDetail未设type字段，CSV Vulns列为空
   统一设为"vulnerability"

3. ICMP权限不足告警精简
   4行告警(listen失败/连接失败/权限不足/切换ping)合并为1行

common/output/stdout_writer.go

@@ -90,7 +90,11 @@ func (w *StdoutNDJSONWriter) flatten(r *ScanResult) *ndjsonRecord {
 
 	rec.Service = strVal(d, "service")
 	rec.Protocol = strVal(d, "protocol")
-	rec.Banner = strVal(d, "banner")
+	if banner := strVal(d, "banner"); len(banner) > 200 {
+		rec.Banner = banner[:200] + "..."
+	} else {
+		rec.Banner = banner
+	}
 	rec.Title = strVal(d, "title")
 	rec.URL = strVal(d, "url")
 	rec.Vulnerability = strVal(d, "vulnerability")