fix: load gog refresh tokens from config keyring

docs/channels/googlechat.md

@@ -74,7 +74,9 @@ If you already use `gog` for Google Workspace, you can reuse its OAuth client +
    ```
 3) Ensure `gog` can access its keyring on the gateway host.
    - `gog` stores refresh tokens in the system keychain by default. citeturn6view0
-   - For headless systems, switch to file keyring + password (see `gog` docs). citeturn6view0
+   - For headless systems (systemd, SSH-only), switch to file keyring + password (see `gog` docs). citeturn6view0
+     - Set `GOG_KEYRING_BACKEND=file` and `GOG_KEYRING_PASSWORD=...` for the gateway service.
+     - The file keyring lives under your gog config directory (for example `~/.config/gogcli/keyring/`).
 4) Verify `gog` is visible to the gateway user:
    ```bash
    gog auth tokens list --json