refactor(vd960Loop): 算法回退到 DLD154V4B，四通道适配

- 用 DLD154V4B vd1_task/per_channel 替换 vds_task 复杂算法
- 移除 FUNCTION_B/二次判断/快速变化/多重确认等增强特性
- 保留平坦性离开算法 (CN200910309382)，每通道独立状态
- 灵敏度表改为 DLD154V4B 4级: {216,108,36,10} / {108,72,18,9}
- 清理废弃类型: FltHistoryManager, Loop_ACS_Info, StageRangeConfig 等
- 首次添加 vd960DBN 完整源码

vd960DBN/SRC/Peripheral/inc/ch32v20x_iwdg.h

@@ -0,0 +1,50 @@
+/********************************** (C) COPYRIGHT  *******************************
+ * File Name          : ch32v20x_iwdg.h
+ * Author             : WCH
+ * Version            : V1.0.0
+ * Date               : 2021/06/06
+ * Description        : This file contains all the functions prototypes for the
+ *                      IWDG firmware library.
+*********************************************************************************
+* Copyright (c) 2021 Nanjing Qinheng Microelectronics Co., Ltd.
+* Attention: This software (modified or not) and binary are used for 
+* microcontroller manufactured by Nanjing Qinheng Microelectronics.
+*******************************************************************************/
+#ifndef __CH32V20x_IWDG_H
+#define __CH32V20x_IWDG_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "ch32v20x.h"
+
+/* IWDG_WriteAccess */
+#define IWDG_WriteAccess_Enable     ((uint16_t)0x5555)
+#define IWDG_WriteAccess_Disable    ((uint16_t)0x0000)
+
+/* IWDG_prescaler */
+#define IWDG_Prescaler_4            ((uint8_t)0x00)
+#define IWDG_Prescaler_8            ((uint8_t)0x01)
+#define IWDG_Prescaler_16           ((uint8_t)0x02)
+#define IWDG_Prescaler_32           ((uint8_t)0x03)
+#define IWDG_Prescaler_64           ((uint8_t)0x04)
+#define IWDG_Prescaler_128          ((uint8_t)0x05)
+#define IWDG_Prescaler_256          ((uint8_t)0x06)
+
+/* IWDG_Flag */
+#define IWDG_FLAG_PVU               ((uint16_t)0x0001)
+#define IWDG_FLAG_RVU               ((uint16_t)0x0002)
+
+void       IWDG_WriteAccessCmd(uint16_t IWDG_WriteAccess);
+void       IWDG_SetPrescaler(uint8_t IWDG_Prescaler);
+void       IWDG_SetReload(uint16_t Reload);
+void       IWDG_ReloadCounter(void);
+void       IWDG_Enable(void);
+FlagStatus IWDG_GetFlagStatus(uint16_t IWDG_FLAG);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif