fix: handle missing current macro scene

src/main/java/com/aps/controller/MacroSceneController.java

@@ -51,7 +51,8 @@ public class MacroSceneController {
     @GetMapping("/current")
     @Operation(summary = "根据用户查询当前主计划场景")
     public R<MacroSceneConfig> current(@RequestParam String userId) {
-        return R.ok(macroSceneService.getSceneByUserId(userId));
+        MacroSceneConfig scene = macroSceneService.getSceneByUserId(userId);
+        return scene == null ? R.ok(null, "error") : R.ok(scene);
     }
 
     @PostMapping("/select")