fix(firmware): move defensive node_id capture before wifi_init_sta()

The original defensive copy in csi_collector_init() (line 172 of main.c)
runs AFTER wifi_init_sta() (line 147), which on some ESP32-S3 devices
corrupts g_nvs_config.node_id back to the Kconfig default of 1.

Reproduced on device 80:b5:4e:c1:be:b8 (ESP32-S3 QFN56 rev v0.2):
  - NVS provisioned with node_id=5
  - Release firmware (no fix): seed receives node_id=1 (clobbered)
  - This patch: seed receives node_id=5 (correct)

Changes:
  - Add csi_collector_set_node_id() called from main.c immediately
    after nvs_config_load(), before wifi_init_sta() runs
  - csi_collector_init() now detects and logs the clobber if early
    capture disagrees with current g_nvs_config value
  - Fallback path preserved: if set_node_id() is never called,
    init() still captures from g_nvs_config (backwards compatible)

Co-Authored-By: claude-flow <ruv@ruv.net>

firmware/esp32-csi-node/main/main.c

@@ -140,6 +140,11 @@ void app_main(void)
     /* Load runtime config (NVS overrides Kconfig defaults) */
     nvs_config_load(&g_nvs_config);
 
+    /* Capture node_id IMMEDIATELY — before wifi_init_sta() can corrupt
+     * g_nvs_config. See #232/#375/#390: WiFi driver init clobbers the struct
+     * on some devices, reverting node_id to the Kconfig default of 1. */
+    csi_collector_set_node_id(g_nvs_config.node_id);
+
     const esp_app_desc_t *app_desc = esp_app_get_description();
     ESP_LOGI(TAG, "ESP32-S3 CSI Node (ADR-018) — v%s — Node ID: %d",
              app_desc->version, g_nvs_config.node_id);