feat(wifi): retain multiple network credentials

components/platform/internal/wifi_portal.h

@@ -15,8 +15,9 @@ typedef struct {
 /**
  * @brief Initialize Wi-Fi portal defaults and seed credentials.
  *
- * This writes the provided SSID/password into NVS if no credentials exist yet.
- * The underlying Wi-Fi manager is initialized lazily when starting STA or AP.
+ * This saves the provided SSID/password as the highest-priority entry while
+ * retaining existing credentials. The underlying Wi-Fi manager is initialized
+ * lazily when starting STA or AP.
  */
 esp_err_t wifi_portal_init_defaults(const char *seed_ssid, const char *seed_password);
 
@@ -50,8 +51,9 @@ esp_err_t wifi_portal_connect_sta(int timeout_ms);
 /**
  * @brief Trial-connect with credentials without persisting them first.
  *
- * On success, the trial credentials atomically replace the saved credential
- * list. On failure, the previous in-memory and NVS credentials remain intact.
+ * On success, the trial credentials are saved as the highest-priority entry
+ * while older credentials are retained. On failure, the previous in-memory
+ * and NVS credentials remain intact.
  */
 esp_err_t wifi_portal_connect_sta_with_credentials(const char *ssid,
                                                    const char *password,