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/acme/dns_provider.go

@@ -0,0 +1,98 @@
+package acme
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/go-acme/lego/v4/challenge"
+	"github.com/go-acme/lego/v4/providers/dns/alidns"
+	"github.com/go-acme/lego/v4/providers/dns/cloudflare"
+	"github.com/go-acme/lego/v4/providers/dns/dnspod"
+	"github.com/go-acme/lego/v4/providers/dns/tencentcloud"
+
+	"github.com/fonu/fonu/internal/ddns"
+)
+
+func newDNS01Provider(provider string, cred ddns.Credentials) (challenge.Provider, error) {
+	switch provider {
+	case "dnspod":
+		cfg := dnspod.NewDefaultConfig()
+		cfg.LoginToken = cred.LoginToken()
+		return dnspod.NewDNSProviderConfig(cfg)
+	case "alidns":
+		cfg := alidns.NewDefaultConfig()
+		cfg.APIKey = cred.Token
+		cfg.SecretKey = cred.Secret
+		return alidns.NewDNSProviderConfig(cfg)
+	case "tencentcloud":
+		cfg := tencentcloud.NewDefaultConfig()
+		cfg.SecretID = cred.Token
+		cfg.SecretKey = cred.Secret
+		return tencentcloud.NewDNSProviderConfig(cfg)
+	case "volcengine":
+		return newVolcengineDNSProvider(cred)
+	default:
+		cfg := cloudflare.NewDefaultConfig()
+		cfg.AuthToken = cred.Token
+		return cloudflare.NewDNSProviderConfig(cfg)
+	}
+}
+
+func dnsProviderName(provider string) string {
+	switch provider {
+	case "dnspod", "alidns", "tencentcloud", "volcengine":
+		return provider
+	default:
+		return "cloudflare"
+	}
+}
+
+type loggingDNSProvider struct {
+	inner challenge.Provider
+	job   *Job
+}
+
+func wrapDNSProvider(inner challenge.Provider, job *Job) challenge.Provider {
+	if job == nil {
+		return inner
+	}
+	return &loggingDNSProvider{inner: inner, job: job}
+}
+
+func (p *loggingDNSProvider) Present(domain, token, keyAuth string) error {
+	record := strings.TrimSuffix(domain, ".")
+	p.job.Info(fmt.Sprintf("添加 DNS TXT 记录: _acme-challenge.%s", record))
+	if err := p.inner.Present(domain, token, keyAuth); err != nil {
+		p.job.Error(fmt.Sprintf("添加 DNS TXT 记录失败: %v", err))
+		return err
+	}
+	p.job.Info("DNS TXT 记录已添加，等待 DNS 传播…")
+	return nil
+}
+
+func (p *loggingDNSProvider) CleanUp(domain, token, keyAuth string) error {
+	p.job.Info("清理 DNS TXT 验证记录…")
+	return p.inner.CleanUp(domain, token, keyAuth)
+}
+
+func validateDNSCredentials(provider string, cred ddns.Credentials) error {
+	if err := cred.Validate(dnsProviderName(provider)); err != nil {
+		return err
+	}
+	if provider == "dnspod" && cred.TokenID == "" {
+		return fmt.Errorf("请先在 DDNS 页面配置 DNSPod ID 和 Token")
+	}
+	if provider == "alidns" && cred.Secret == "" {
+		return fmt.Errorf("请先在 DDNS 页面配置阿里云 AccessKey")
+	}
+	if provider == "tencentcloud" && cred.Secret == "" {
+		return fmt.Errorf("请先在 DDNS 页面配置腾讯云 SecretKey")
+	}
+	if provider == "volcengine" && cred.Secret == "" {
+		return fmt.Errorf("请先在 DDNS 页面配置火山引擎 Secret Access Key")
+	}
+	if provider != "dnspod" && provider != "alidns" && provider != "tencentcloud" && provider != "volcengine" && cred.Token == "" {
+		return fmt.Errorf("请先在 DDNS 页面配置 Cloudflare API Token")
+	}
+	return nil
+}