fix:get-datetime接口应当包装vo

src/main/java/com/iflytop/colortitration/app/controller/SystemController.java

@@ -38,7 +38,7 @@ public class SystemController {
 
     @Operation(summary = "获取当前系统时间")
     @GetMapping("/get-datetime")
-    public Result<?> getDatetime() {
+    public Result<TimeResponseVO> getDatetime() {
         return Result.success(new TimeResponseVO(Instant.now().toEpochMilli()));
     }