feat(vd960DBN): MQTT/TCP report_config 支持完整7参数配置

- 新增 ReportConfig 结构体 (sensor_type/enable/once/env_eval/interval/ack_required/timeout)
- net_srv.c: MQTT report_config handler — 查询/设置均返回完整配置JSON
- tcp_json_srv.c: TCP JSON handle_report_config 同步升级，兼容旧 active_report
- iot_mqtt_srv.c: g_report_active → g_report_cfg.enable
- g_report_active 全局变量替换为 g_report_cfg 结构体

vd960DBN/BLE/OnlyUpdateApp_Peripheral/APP/include/tcp_json_srv.h

@@ -58,6 +58,19 @@ typedef struct {
     uint32_t deadline;       // ms deadline for timeout
 } TcpJsonPending;
 
+/*===========================================================================
+ * Report Config
+ *===========================================================================*/
+typedef struct {
+    uint8_t  enable;          // 0=off, 1=on
+    uint8_t  sensor_type;     // Sensor type, default 12
+    uint8_t  once;            // 0=periodic, 1=single report
+    uint8_t  env_eval;        // 0=skip, 1=environment evaluation
+    uint16_t interval;        // Report interval in seconds
+    uint8_t  ack_required;    // 0=fire-and-forget, 1=ACK required
+    uint16_t timeout;         // Timeout in ms
+} ReportConfig;
+
 /*===========================================================================
  * Externs
  *===========================================================================*/
@@ -70,7 +83,7 @@ extern uint32_t g_json_last_comm_ts;     // Last communication timestamp (ms)
 extern uint32_t g_json_last_connect_ts;  // Last client connect timestamp (ms)
 extern uint8_t  g_json_restart_count;    // Auto-restart counter
 extern uint32_t g_json_restart_cooldown; // Cooldown deadline (ms)
-extern uint8_t  g_report_active;          // 0=inactive 1=active report
+extern ReportConfig g_report_cfg;        // Active report configuration
 
 /*===========================================================================
  * API