feat: Add new model management features

- Implement `/api/channel/models_enabled` endpoint to retrieve enabled models
- Add `EnabledListModels` handler in controller
- Create new `ModelRatioNotSetEditor` component for managing unset model ratios
- Update router to include new models_enabled route
- Add internationalization support for new model management UI
- Include GPT-4.5 preview model in OpenAI model list

controller/model.go

@@ -216,6 +216,13 @@ func DashboardListModels(c *gin.Context) {
 	})
 }
 
+func EnabledListModels(c *gin.Context) {
+	c.JSON(200, gin.H{
+		"success": true,
+		"data":    model.GetEnabledModels(),
+	})
+}
+
 func RetrieveModel(c *gin.Context) {
 	modelId := c.Param("model")
 	if aiModel, ok := openAIModelsMap[modelId]; ok {