chore: snapshot before shared RS485 bus integration

components/meter_manager/driver/meter_zigbee/meter_zigbee.c

@@ -8,6 +8,7 @@
 #include "driver/uart.h"
 #include "driver/gpio.h"
 #include "meter_events.h"
+#include "esp_timer.h"
 
 #define TAG "meter_zigbee"
 
@@ -76,11 +77,19 @@ static inline int32_t tuya_power16_to_signed(uint16_t p)
 
 static void meter_zigbee_post_event(void)
 {
+    int32_t watt_total =
+        (int32_t)meter_data.watt[PHASE_L1] +
+        (int32_t)meter_data.watt[PHASE_L2] +
+        (int32_t)meter_data.watt[PHASE_L3];
+
     meter_event_data_t evt = {
         .source = "GRID",
         .frequency = meter_data.frequency,
         .power_factor = meter_data.power_factor,
-        .total_energy = meter_data.total_energy};
+        .total_energy = meter_data.total_energy,
+        .watt_total = watt_total,
+        .timestamp_us = esp_timer_get_time(),
+    };
 
     memcpy(evt.vrms, meter_data.vrms, sizeof(evt.vrms));
     memcpy(evt.irms, meter_data.irms, sizeof(evt.irms));