chore: 初始提交 Fonu 1.0.2

- 公网反代：Nginx 状态卡片（版本 / 运行状态 / 配置校验 / 端口监听）
- 部署设置第一、二梯队（HTTPS 开关、安全头、限流、连接数、仅中国大陆 IP）
- 隧道检测兼容 frps v0.68 / v0.71（V2 与旧版端点）
- 恢复被清空的 internal/frp/store.go、internal/api/ddns_handler.go、web/src/views/DdnsView.vue

internal/discovery/service.go

@@ -0,0 +1,127 @@
+package discovery
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"net/http"
+	"strings"
+	"time"
+)
+
+type Service struct {
+	client *http.Client
+}
+
+type Result struct {
+	Name       string `json:"name"`
+	Port       int    `json:"port"`
+	Host       string `json:"host"`
+	Upstream   string `json:"upstream"`
+	Detected   bool   `json:"detected"`
+	Platform   string `json:"platform"`
+	Title      string `json:"title,omitempty"`
+	Suggestion string `json:"suggestion,omitempty"`
+}
+
+type catalogEntry struct {
+	Name     string
+	Port     int
+	Platform string
+	Keywords []string
+}
+
+var catalog = []catalogEntry{
+	{Name: "飞牛 fnOS", Port: 5666, Platform: "fnos", Keywords: []string{"fnos", "飞牛", "fnos.cn"}},
+	{Name: "AList", Port: 5244, Platform: "alist", Keywords: []string{"alist"}},
+	{Name: "Jellyfin", Port: 8096, Platform: "jellyfin", Keywords: []string{"jellyfin"}},
+	{Name: "PhotoPrism", Port: 2342, Platform: "photoprism", Keywords: []string{"photoprism"}},
+	{Name: "qBittorrent", Port: 8080, Platform: "qbittorrent", Keywords: []string{"qbittorrent"}},
+	{Name: "Portainer", Port: 9000, Platform: "portainer", Keywords: []string{"portainer"}},
+}
+
+func New() *Service {
+	return &Service{
+		client: &http.Client{Timeout: 2 * time.Second},
+	}
+}
+
+func (s *Service) Scan(ctx context.Context, host string) []Result {
+	host = strings.TrimSpace(host)
+	if host == "" {
+		host = "127.0.0.1"
+	}
+	out := make([]Result, 0, len(catalog))
+	for _, item := range catalog {
+		result := Result{
+			Name:     item.Name,
+			Port:     item.Port,
+			Host:     host,
+			Upstream: fmt.Sprintf("http://%s:%d", host, item.Port),
+			Platform: item.Platform,
+		}
+		if !s.portOpen(ctx, host, item.Port) {
+			out = append(out, result)
+			continue
+		}
+		result.Detected = true
+		title, body := s.probeHTTP(ctx, host, item.Port)
+		result.Title = title
+		if s.matchPlatform(item, title, body) {
+			result.Platform = item.Platform
+			if item.Platform == "fnos" {
+				result.Suggestion = "检测到飞牛 fnOS 服务，可使用 nas.<域名> 创建反向代理"
+			}
+		}
+		out = append(out, result)
+	}
+	return out
+}
+
+func (s *Service) portOpen(ctx context.Context, host string, port int) bool {
+	dialer := net.Dialer{Timeout: 800 * time.Millisecond}
+	conn, err := dialer.DialContext(ctx, "tcp", fmt.Sprintf("%s:%d", host, port))
+	if err != nil {
+		return false
+	}
+	conn.Close()
+	return true
+}
+
+func (s *Service) probeHTTP(ctx context.Context, host string, port int) (string, string) {
+	url := fmt.Sprintf("http://%s:%d/", host, port)
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return "", ""
+	}
+	resp, err := s.client.Do(req)
+	if err != nil {
+		return "", ""
+	}
+	defer resp.Body.Close()
+	bodyBytes := make([]byte, 4096)
+	n, _ := resp.Body.Read(bodyBytes)
+	body := strings.ToLower(string(bodyBytes[:n]))
+	title := extractTitle(body)
+	return title, body
+}
+
+func (s *Service) matchPlatform(item catalogEntry, title, body string) bool {
+	content := strings.ToLower(title + " " + body)
+	for _, keyword := range item.Keywords {
+		if strings.Contains(content, strings.ToLower(keyword)) {
+			return true
+		}
+	}
+	return false
+}
+
+func extractTitle(body string) string {
+	lower := strings.ToLower(body)
+	start := strings.Index(lower, "<title>")
+	end := strings.Index(lower, "</title>")
+	if start >= 0 && end > start {
+		return strings.TrimSpace(body[start+7 : end])
+	}
+	return ""
+}