fix(ai): 助手 chat 端点补 AdminAuth——前端浮球已限 admin,后端同步兜底防普通用户直调 API 耗 token

backend/routers/router.go

@@ -130,7 +130,7 @@ func SetupRouter() *gin.Engine {
 		ai.GET("/config", middleware.AdminAuth(), aiCtrl.GetConfig)
 		ai.PUT("/config", middleware.AdminAuth(), aiCtrl.SaveConfig)
 		ai.POST("/config/test", middleware.AdminAuth(), aiCtrl.TestConfig)
-		ai.POST("/chat", middleware.RequirePro(), aiCtrl.Chat)
+		ai.POST("/chat", middleware.AdminAuth(), middleware.RequirePro(), aiCtrl.Chat)
 		ai.GET("/runs", aiCtrl.ListRuns)
 		ai.GET("/runs/:id", aiCtrl.GetRun)
 	}