feat(message-gateway): add admin channel CRUD APIs

internal/apps/admin/message_gateway/routers.go

@@ -0,0 +1,20 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+// Package message_gateway provides admin HTTP APIs for messaging channels.
+package message_gateway
+
+import "github.com/gin-gonic/gin"
+
+// RegisterRoutes mounts admin message-gateway APIs under /admin.
+func RegisterRoutes(adminRouter *gin.RouterGroup) {
+	g := adminRouter.Group("/message-gateway")
+	{
+		g.GET("/channels/definitions", ListChannelDefinitions)
+		g.GET("/channels", ListChannels)
+		g.POST("/channels", CreateChannel)
+		g.PATCH("/channels/:id", UpdateChannel)
+		g.DELETE("/channels/:id", DeleteChannel)
+		g.POST("/channels/:id/test", TestChannel)
+	}
+}