fix(esp32): use runtime node_id from NVS in outgoing packets

[melodykke]

Summary

Fix an ESP32 firmware issue where outgoing packets could use the compile-time node ID instead of the runtime node ID loaded from NVS.

In multi-node setups, this could cause a provisioned board to still appear with the wrong node_id on the receiver side.

Root Cause

Some packet serialization paths were still using CONFIG_CSI_NODE_ID instead of g_nvs_config.node_id.

That meant NVS provisioning could succeed while transmitted packets still carried the compile-time default.

Changes

Use g_nvs_config.node_id consistently in outgoing packet paths.

Validation

Tested with a real ESP32-S3 setup.

• provisioned a board with node_id=2 via NVS
• rebuilt and reflashed firmware
• confirmed RuView then reported node_id=2 correctly

Impact

This makes runtime node provisioning behave correctly for multi-node deployments.