gateway_state.json preserves per-platform entries across restarts, so a gateway
that once ran without TELEGRAM_BOT_TOKEN and then stopped kept reporting
'fatal / No bot token configured' on the Channels/Messaging pages even after the
user saved a token — the Desktop showed 'Saved' on both fields next to the error.
Only a live gateway's verdict describes current config; when no gateway is running
the platform reads gateway_stopped with no error.
Teknium