refactor(integration): 重构集成服务的降级机制

-移除各服务自定义的降级服务类，统一降级逻辑
- 新增 IntegrationFallbackService作为通用降级服务
- 更新设备和景区服务的降级处理方式
- 优化降级缓存管理，增加统计信息和批量清理功能
- 调整 API 接口，移除扁平化批量更新等相关方法

src/main/java/com/ycwl/basic/controller/pc/DeviceV2Controller.java

@@ -399,21 +399,6 @@ public class DeviceV2Controller {
         }
     }
 
-    /**
-     * 扁平化批量更新设备配置
-     */
-    @PostMapping("/{id}/config/flat-batch")
-    public ApiResponse<String> batchFlatUpdateDeviceConfig(@PathVariable Long id, 
-                                                          @RequestBody Map<String, Object> configs) {
-        log.info("扁平化批量更新设备配置, deviceId: {}, configs count: {}", id, configs.size());
-        try {
-            deviceConfigIntegrationService.batchFlatUpdateDeviceConfig(id, configs);
-            return ApiResponse.success("设备配置批量更新成功");
-        } catch (Exception e) {
-            log.error("扁平化批量更新设备配置失败, deviceId: {}", id, e);
-            return ApiResponse.fail("扁平化批量更新设备配置失败: " + e.getMessage());
-        }
-    }
 
     /**
      * 更新设备配置
@@ -431,27 +416,6 @@ public class DeviceV2Controller {
         }
     }
 
-    /**
-     * 配置摄像头参数（快捷方法）
-     */
-    @PutMapping("/{id}/config/camera")
-    public ApiResponse<String> configureCameraParams(@PathVariable Long id, @RequestBody Map<String, Object> request) {
-        String ipAddress = (String) request.get("ipAddress");
-        String resolution = (String) request.get("resolution");
-        Integer framerate = request.get("framerate") != null ? Integer.valueOf(request.get("framerate").toString()) : null;
-        String protocol = (String) request.get("protocol");
-        String username = (String) request.get("username");
-        String password = (String) request.get("password");
-        
-        log.info("配置摄像头参数, deviceId: {}, ipAddress: {}, resolution: {}", id, ipAddress, resolution);
-        try {
-            deviceConfigIntegrationService.configureCameraParams(id, ipAddress, resolution, framerate, protocol, username, password);
-            return ApiResponse.success("摄像头参数配置成功");
-        } catch (Exception e) {
-            log.error("配置摄像头参数失败, deviceId: {}", id, e);
-            return ApiResponse.fail("配置摄像头参数失败: " + e.getMessage());
-        }
-    }
 
     /**
      * 删除设备配置