fix(aiot): 修复 backfill-device-id 被全局响应拦截器误转型导致 500

GlobalResponseAdvice:65 对 LinkedHashMap 中的 "status" 键强转 Integer，
但 backfill 端点放入的是字符串 "success"，触发 ClassCastException。

- backfill 返回 Map 的键从 "status" 改为 "result" 避免冲突
- GlobalResponseAdvice 增加 instanceof Integer 类型检查，防止其他端点踩坑

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/main/java/com/genersoft/iot/vmp/aiot/controller/AiConfigController.java

@@ -162,7 +162,7 @@ public class AiConfigController {
         int updatedRois = roiMapper.updateAllDeviceId(targetDeviceId);
         result.put("rois_updated", updatedRois);
 
-        result.put("status", "success");
+        result.put("result", "success");
         result.put("device_id", targetDeviceId);
         log.info("[AiConfig] 统一 device_id 完成: deviceId={}, deletedDevices={}, updatedRois={}",
                 targetDeviceId, deleted, updatedRois);

src/main/java/com/genersoft/iot/vmp/conf/GlobalResponseAdvice.java

@@ -62,7 +62,8 @@ public class GlobalResponseAdvice implements ResponseBodyAdvice<Object> {
 
         if (body instanceof LinkedHashMap) {
             LinkedHashMap<String, Object> bodyMap = (LinkedHashMap<String, Object>) body;
-            if (bodyMap.get("status") != null && (Integer)bodyMap.get("status") != 200) {
+            Object statusVal = bodyMap.get("status");
+            if (statusVal instanceof Integer && (Integer) statusVal != 200) {
                 return body;
             }
         }