handler: move mqttping into handler package; clean up main.go

cmd/server/main.go

@@ -74,19 +74,8 @@ func main() {
 	r.GET("/hello", handler.Hello)
 	r.POST("/login", handler.Login)
 
-	// mqttping endpoint: publish current timestamp to MQTT topic
-	r.POST("/mqttping", func(c *gin.Context) {
-		ts := time.Now().Format(time.RFC3339)
-		if mq == nil {
-			c.JSON(http.StatusServiceUnavailable, gin.H{"error": "mqtt not connected"})
-			return
-		}
-		if err := mq.Publish(cfg.MQTT.Topic, []byte(ts)); err != nil {
-			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
-			return
-		}
-		c.JSON(http.StatusOK, gin.H{"timestamp": ts})
-	})
+	// mqttping endpoint handled by internal/handler
+	r.POST("/mqttping", handler.MQTTPing)
 
 	// Protected routes
 	auth := r.Group("/")