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/frp-1.0.2/sync.go

@@ -0,0 +1,42 @@
+package frp
+
+import (
+	"strings"
+
+	"github.com/fonu/fonu/internal/proxy"
+)
+
+func DomainsFromProxyRules(rules []proxy.Rule) []string {
+	seen := make(map[string]bool)
+	var domains []string
+	for _, rule := range rules {
+		if !rule.Enabled {
+			continue
+		}
+		for _, host := range rule.Hostnames() {
+			if host == "" || seen[host] {
+				continue
+			}
+			seen[host] = true
+			domains = append(domains, host)
+		}
+	}
+	return domains
+}
+
+func MergeDomains(existing, incoming []string) []string {
+	seen := make(map[string]bool)
+	var out []string
+	for _, list := range [][]string{existing, incoming} {
+		for _, d := range list {
+			d = strings.TrimSpace(d)
+			key := strings.ToLower(d)
+			if d == "" || seen[key] {
+				continue
+			}
+			seen[key] = true
+			out = append(out, d)
+		}
+	}
+	return out
+}