feat: v2.1.0 核心重构与功能增强

## 架构重构
- 全局变量消除，迁移至 Config/State 对象
- SMB 插件融合（smb/smb2/smbghost/smbinfo）
- 服务探测重构，实现 Nmap 风格 fallback 机制
- 输出系统重构，TXT 实时刷盘 + 双写机制
- i18n 框架升级至 go-i18n

## 性能优化
- 正则表达式预编译
- 内存优化 map[string]struct{}
- 并发指纹匹配
- SOCKS5 连接复用
- 滑动窗口调度 + 自适应线程池

## 新功能
- Web 管理界面
- 多格式 POC 适配（xray/afrog）
- 增强指纹库（3139条）
- Favicon hash 指纹识别
- 插件选择性编译（Build Tags）
- fscan-lab 靶场环境
- 默认端口扩展（62→133）

## 构建系统
- 添加 no_local tag 支持排除本地插件
- 多版本构建：fscan/fscan-nolocal/fscan-web
- CI 添加 snapshot 模式支持仅测试构建

## Bug 修复
- 修复 120+ 个问题，包括 RDP panic、批量扫描漏报、
  JSON 输出格式、Redis 检测、Context 超时等

## 测试增强
- 单元测试覆盖率 74-100%
- 并发安全测试
- 集成测试（Web/端口/服务/SSH/ICMP）

tools/perftest/perftest.go

@@ -0,0 +1,179 @@
+// perftest - fscan 可扩展性测试工具
+// 测量不同线程数下的扫描性能，生成 CSV 数据用于绘图
+package main
+
+import (
+	"encoding/csv"
+	"flag"
+	"fmt"
+	"os"
+	"os/exec"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+)
+
+type Result struct {
+	Threads   int
+	Duration  float64 // 秒
+	PortsRate float64 // ports/sec
+	FailRate  float64 // 失败率%
+}
+
+func main() {
+	target := flag.String("target", "", "扫描目标 (如 192.168.1.0/24)")
+	ports := flag.String("ports", "22,80,443,3389,8080", "端口列表")
+	threads := flag.String("threads", "100,200,400,600,800,1000", "线程数列表，逗号分隔")
+	repeat := flag.Int("repeat", 3, "每个线程数重复次数")
+	output := flag.String("o", "perf_results.csv", "输出CSV文件")
+	flag.Parse()
+
+	if *target == "" {
+		fmt.Println("用法: perftest -target 192.168.1.0/24 [-ports 22,80,443] [-threads 100,200,400]")
+		os.Exit(1)
+	}
+
+	threadList := parseIntList(*threads)
+	results := []Result{}
+
+	fmt.Printf("=== fscan 可扩展性测试 ===\n")
+	fmt.Printf("目标: %s\n", *target)
+	fmt.Printf("端口: %s\n", *ports)
+	fmt.Printf("线程数: %v\n", threadList)
+	fmt.Printf("重复次数: %d\n\n", *repeat)
+
+	for _, t := range threadList {
+		var totalDuration float64
+		var totalRate float64
+
+		fmt.Printf("[线程=%d] ", t)
+		for i := 0; i < *repeat; i++ {
+			fmt.Printf(".")
+			duration, rate := runFscan(*target, *ports, t)
+			totalDuration += duration
+			totalRate += rate
+		}
+
+		avgDuration := totalDuration / float64(*repeat)
+		avgRate := totalRate / float64(*repeat)
+
+		results = append(results, Result{
+			Threads:   t,
+			Duration:  avgDuration,
+			PortsRate: avgRate,
+		})
+		fmt.Printf(" 平均: %.2fs, %.1f ports/sec\n", avgDuration, avgRate)
+	}
+
+	writeCSV(*output, results)
+	fmt.Printf("\n结果已保存到: %s\n", *output)
+	printPlotCommand(*output)
+}
+
+func runFscan(target, ports string, threads int) (duration float64, rate float64) {
+	args := []string{
+		"-h", target,
+		"-p", ports,
+		"-t", strconv.Itoa(threads),
+		"-np", "-nopoc", // 禁用ping和poc，只测端口扫描
+		"-o", "/dev/null",
+	}
+
+	start := time.Now()
+	cmd := exec.Command("./fscan", args...)
+	output, _ := cmd.CombinedOutput()
+	duration = time.Since(start).Seconds()
+
+	// 从输出解析扫描的端口数
+	portCount := extractPortCount(string(output), target, ports)
+	if duration > 0 {
+		rate = float64(portCount) / duration
+	}
+	return
+}
+
+func extractPortCount(output, target, ports string) int {
+	// 尝试从 "扫描完成" 行提取
+	re := regexp.MustCompile(`扫描完成.*?(\d+).*?端口`)
+	if matches := re.FindStringSubmatch(output); len(matches) > 1 {
+		count, _ := strconv.Atoi(matches[1])
+		return count
+	}
+
+	// 估算: IP数 × 端口数
+	ipCount := estimateIPCount(target)
+	portCount := len(strings.Split(ports, ","))
+	return ipCount * portCount
+}
+
+func estimateIPCount(target string) int {
+	if strings.Contains(target, "/24") {
+		return 254
+	}
+	if strings.Contains(target, "/16") {
+		return 65534
+	}
+	return 1
+}
+
+func parseIntList(s string) []int {
+	parts := strings.Split(s, ",")
+	result := make([]int, 0, len(parts))
+	for _, p := range parts {
+		if n, err := strconv.Atoi(strings.TrimSpace(p)); err == nil {
+			result = append(result, n)
+		}
+	}
+	return result
+}
+
+func writeCSV(filename string, results []Result) {
+	f, err := os.Create(filename)
+	if err != nil {
+		fmt.Printf("无法创建文件: %v\n", err)
+		return
+	}
+	defer func() { _ = f.Close() }()
+
+	w := csv.NewWriter(f)
+	_ = w.Write([]string{"threads", "duration_sec", "ports_per_sec"})
+	for _, r := range results {
+		_ = w.Write([]string{
+			strconv.Itoa(r.Threads),
+			fmt.Sprintf("%.3f", r.Duration),
+			fmt.Sprintf("%.1f", r.PortsRate),
+		})
+	}
+	w.Flush()
+}
+
+func printPlotCommand(csvFile string) {
+	fmt.Println("\n=== 绘图命令 ===")
+	fmt.Println("\n# gnuplot:")
+	fmt.Printf(`gnuplot -e "
+set terminal png size 800,600;
+set output 'scalability.png';
+set title 'fscan Scalability';
+set xlabel 'Threads';
+set ylabel 'Ports/sec';
+set grid;
+plot '%s' using 1:3 with linespoints title 'Throughput'
+"
+`, csvFile)
+
+	fmt.Println("\n# Python matplotlib:")
+	fmt.Println(`python -c "
+import pandas as pd
+import matplotlib.pyplot as plt
+df = pd.read_csv('` + csvFile + `')
+plt.figure(figsize=(10,6))
+plt.plot(df['threads'], df['ports_per_sec'], 'o-', linewidth=2, markersize=8)
+plt.xlabel('Threads')
+plt.ylabel('Ports/sec')
+plt.title('fscan Scalability Chart')
+plt.grid(True)
+plt.savefig('scalability.png', dpi=150)
+print('已保存: scalability.png')
+"`)
+}