Previously, setting SLACK_BOT_TOKEN in .env would unconditionally enable
the Slack gateway adapter regardless of `slack.enabled: false` in config.yaml.
This caused spurious "SLACK_APP_TOKEN not set" errors when the token was
used only by skills (e.g. cron jobs that send Slack messages) rather than
for the Hermes messaging gateway.
Now, enabled: false in config.yaml is respected — the token is stored so
skills can still use it, but the gateway adapter is not activated.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>