feat: 新增 SafeW 出站通知渠道

通过 Bot API sendMessage 投递渲染后的通知，MarkdownV2 自动转义标题与正文。

Co-authored-by: Cursor <cursoragent@cursor.com>

internal/adapter/safew.go

@@ -0,0 +1,138 @@
+package adapter
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+)
+
+const safewAPIBase = "https://api.safew.bot"
+
+type SafeWSender struct {
+	apiBase string
+}
+
+type safewConfig struct {
+	Token  string          `json:"token"`
+	ChatID json.RawMessage `json:"chat_id"`
+}
+
+type safewMessage struct {
+	ChatID    string `json:"chat_id"`
+	Text      string `json:"text"`
+	ParseMode string `json:"parse_mode"`
+}
+
+type safewAPIResponse struct {
+	OK          bool   `json:"ok"`
+	Description string `json:"description"`
+}
+
+func (s *SafeWSender) Type() string { return "safew" }
+
+func (s *SafeWSender) Send(title, content string, config json.RawMessage) error {
+	var cfg safewConfig
+	if err := json.Unmarshal(config, &cfg); err != nil {
+		return fmt.Errorf("parse safew config: %w", err)
+	}
+	token := strings.TrimSpace(cfg.Token)
+	if token == "" {
+		return fmt.Errorf("safew: token is required")
+	}
+	chatID, err := parseSafewChatID(cfg.ChatID)
+	if err != nil {
+		return err
+	}
+
+	payload := safewMessage{
+		ChatID:    chatID,
+		Text:      "*" + escapeMarkdownV2(title) + "*\n" + escapeMarkdownV2(content),
+		ParseMode: "MarkdownV2",
+	}
+	body, err := json.Marshal(payload)
+	if err != nil {
+		return fmt.Errorf("safew marshal: %w", err)
+	}
+
+	resp, err := http.Post(s.endpoint(token), "application/json", bytes.NewReader(body))
+	if err != nil {
+		return fmt.Errorf("safew send: %w", err)
+	}
+	defer resp.Body.Close()
+
+	respBody, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return fmt.Errorf("safew read: %w", err)
+	}
+	if resp.StatusCode >= 400 {
+		desc := safewErrorDescription(respBody)
+		if desc != "" {
+			return fmt.Errorf("safew returned status %d: %s", resp.StatusCode, desc)
+		}
+		return fmt.Errorf("safew returned status %d", resp.StatusCode)
+	}
+
+	var api safewAPIResponse
+	if err := json.Unmarshal(respBody, &api); err != nil {
+		return fmt.Errorf("safew decode: %w", err)
+	}
+	if !api.OK {
+		desc := api.Description
+		if desc == "" {
+			desc = "ok=false"
+		}
+		return fmt.Errorf("safew: %s", desc)
+	}
+	return nil
+}
+
+func (s *SafeWSender) endpoint(token string) string {
+	base := s.apiBase
+	if base == "" {
+		base = safewAPIBase
+	}
+	return strings.TrimRight(base, "/") + "/bot" + token + "/sendMessage"
+}
+
+func parseSafewChatID(raw json.RawMessage) (string, error) {
+	raw = bytes.TrimSpace(raw)
+	if len(raw) == 0 || string(raw) == "null" {
+		return "", fmt.Errorf("safew: chat_id is required")
+	}
+	if raw[0] == '"' {
+		var id string
+		if err := json.Unmarshal(raw, &id); err != nil {
+			return "", fmt.Errorf("safew: invalid chat_id: %w", err)
+		}
+		id = strings.TrimSpace(id)
+		if id == "" {
+			return "", fmt.Errorf("safew: chat_id is required")
+		}
+		return id, nil
+	}
+	return string(raw), nil
+}
+
+func safewErrorDescription(body []byte) string {
+	var api safewAPIResponse
+	if err := json.Unmarshal(body, &api); err != nil {
+		return strings.TrimSpace(string(body))
+	}
+	return api.Description
+}
+
+func escapeMarkdownV2(s string) string {
+	var b strings.Builder
+	b.Grow(len(s))
+	for _, r := range s {
+		switch r {
+		case '_', '*', '[', ']', '(', ')', '~', '`', '>', '#', '+', '-', '=', '|', '{', '}', '.', '!', '\\':
+			b.WriteByte('\\')
+		}
+		b.WriteRune(r)
+	}
+	return b.String()
+}