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/notify/telegram.go

@@ -0,0 +1,69 @@
+package notify
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+)
+
+func SendTelegram(ctx context.Context, client *http.Client, cfg RuntimeConfig, content AlertContent) error {
+	token := strings.TrimSpace(cfg.TelegramToken)
+	if token == "" {
+		return fmt.Errorf("Telegram Bot Token 未配置")
+	}
+	chatID := strings.TrimSpace(cfg.Telegram.ChatID)
+	if chatID == "" {
+		return fmt.Errorf("Telegram Chat ID 未配置")
+	}
+
+	payload := map[string]string{
+		"chat_id":    chatID,
+		"text":       content.HTMLBody,
+		"parse_mode": "HTML",
+	}
+	body, _ := json.Marshal(payload)
+	endpoint := "https://api.telegram.org/bot" + token + "/sendMessage"
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, endpoint, bytes.NewReader(body))
+	if err != nil {
+		return err
+	}
+	req.Header.Set("Content-Type", "application/json")
+
+	httpClient := client
+	if httpClient == nil {
+		httpClient = &http.Client{Timeout: 15 * time.Second}
+	}
+	if proxyURL := strings.TrimSpace(cfg.Telegram.ProxyURL); proxyURL != "" {
+		parsed, err := url.Parse(proxyURL)
+		if err != nil {
+			return fmt.Errorf("Telegram 代理地址无效")
+		}
+		httpClient = &http.Client{
+			Timeout: 15 * time.Second,
+			Transport: &http.Transport{
+				Proxy: http.ProxyURL(parsed),
+			},
+		}
+	}
+
+	resp, err := httpClient.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode >= 400 {
+		raw, _ := io.ReadAll(io.LimitReader(resp.Body, 512))
+		if len(raw) > 0 {
+			return fmt.Errorf("Telegram 请求失败 (%d): %s", resp.StatusCode, strings.TrimSpace(string(raw)))
+		}
+		return fmt.Errorf("Telegram 请求失败 (%d)", resp.StatusCode)
+	}
+	return nil
+}