chore: snapshot before shared RS485 bus integration

components/meter_manager/include/meter_manager.h

@@ -14,6 +14,7 @@ typedef enum {
     METER_TYPE_ORNO516,        // ORNO-516
     METER_TYPE_ORNO526,        // ORNO-516
     METER_TYPE_DDS661,         // DDS-661
+    METER_TYPE_DDS665,         // DDS-665
     METER_TYPE_DTS6619,        // dts6619
     METER_TYPE_MONO_ZIGBEE,    // Zigbee single-phase
     METER_TYPE_TRIF_ZIGBEE,     // Zigbee three-phase
@@ -105,6 +106,16 @@ esp_err_t meter_manager_grid_set_model(meter_type_t meter_type);
  */
 meter_type_t meter_manager_grid_get_model(void);
 
+
+/**
+ * @brief Atomically sets GRID and EVSE meter types, saves them to storage,
+ *        then reinitializes/restarts the configured meters.
+ *
+ * This is preferred when changing both meters from the REST API because it
+ * avoids transient mixed Modbus masters on the same RS485 bus.
+ */
+esp_err_t meter_manager_set_models(meter_type_t grid_type, meter_type_t evse_type);
+
 /**
  * @brief Utility functions
  */