refactor(msg_gateway): restructure and rename message_gateway aligned with custom_example

backend/plugins/domain/msg_gateway/push/slack.go

@@ -0,0 +1,69 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+package push
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"github.com/nikoksr/notify"
+	"github.com/nikoksr/notify/service/slack"
+)
+
+func init() {
+	Register("slack", &SlackPusher{})
+}
+
+// SlackPusher 基于 nikoksr/notify 的 Slack 推送实现
+type SlackPusher struct{}
+
+// Send 发送 Slack 通知
+func (p *SlackPusher) Send(ctx context.Context, cfg Config, target string, body map[string]any, _ string, _ map[string]any) (string, error) {
+	token := cfg.Key
+	if token == "" {
+		token = cfg.Secret
+	}
+	channelID := cfg.URL
+	if target != "" {
+		channelID = target
+	}
+	if channelID == "" {
+		channelID = cfg.Other
+	}
+
+	if token == "" {
+		return "", errors.New("slack: bot/api token is required")
+	}
+	if channelID == "" {
+		return "", errors.New("slack: channel ID is required")
+	}
+
+	title := bodyTitle(body)
+	content := bodyContent(body, "*%s*: %v", "\n")
+
+	slackService := slack.New(token)
+	slackService.AddReceivers(channelID)
+
+	notifier := notify.New()
+	notifier.UseServices(slackService)
+
+	if err := notifier.Send(ctx, title, content); err != nil {
+		return "", fmt.Errorf("slack: notify send failed: %w", err)
+	}
+
+	return "ok", nil
+}
+
+// ValidateConfig 校验 Slack 配置
+func (p *SlackPusher) ValidateConfig(cfg Config) error {
+	token := cfg.Key
+	if token == "" {
+		token = cfg.Secret
+	}
+	if token == "" {
+		return errors.New("slack token is required")
+	}
+	return nil
+}