feat(push): validate push channels presence before enabling push event

- Reject toggling an event to enabled in ToggleEvent handler if channels list is empty.
- Add model-level validation in PushEvent.Validate() to prevent enabling events without channels during creation/updates.
- Update TestPushRouters/toggle_event_status unit test to cover this verification.

internal/apps/admin/push/push_test.go

@@ -363,11 +363,20 @@ func TestPushRouters(t *testing.T) {
 		var event model.PushEvent
 		dbConn.First(&event)
 
+		// 1. 未配置任何渠道时开启，应该被拒绝
 		req, _ := http.NewRequest("POST", "/api/v1/admin/push/events/"+strconv.FormatUint(event.ID, 10)+"/toggle", nil)
 		w := httptest.NewRecorder()
 		r.ServeHTTP(w, req)
+		assert.Equal(t, http.StatusBadRequest, w.Code)
 
-		assert.Equal(t, http.StatusOK, w.Code)
+		// 2. 为该事件关联渠道后，再切换开启，应当成功
+		event.Channels = []string{"email"}
+		dbConn.Save(&event)
+
+		req2, _ := http.NewRequest("POST", "/api/v1/admin/push/events/"+strconv.FormatUint(event.ID, 10)+"/toggle", nil)
+		w2 := httptest.NewRecorder()
+		r.ServeHTTP(w2, req2)
+		assert.Equal(t, http.StatusOK, w2.Code)
 
 		var updated model.PushEvent
 		dbConn.First(&updated)

internal/apps/admin/push/routers.go

@@ -351,6 +351,10 @@ func ToggleEvent(c *gin.Context) {
 	}
 
 	event.Enabled = !event.Enabled
+	if event.Enabled && len(event.Channels) == 0 {
+		c.JSON(http.StatusBadRequest, response.Err("cannot enable event without any push channels configured"))
+		return
+	}
 	if err := db.DB(c.Request.Context()).Model(&event).Update("enabled", event.Enabled).Error; err != nil {
 		c.JSON(http.StatusInternalServerError, response.Err(err.Error()))
 		return

internal/model/push_event.go

@@ -46,6 +46,9 @@ func (pe *PushEvent) Validate() error {
 	if pe.Template == "" {
 		return errors.New("event template is required")
 	}
+	if pe.Enabled && len(pe.Channels) == 0 {
+		return errors.New("cannot enable event without any push channels configured")
+	}
 	return nil
 }