hermes - 💡(How to fix) Fix Feature request: option to disable/customize gateway shutdown notification

Bug Description

When Hermes Gateway restarts (e.g. during an automatic update via cron job), users receive a system notification message:

⚠️ Gateway shutting down — Your current task will be interrupted.

This message is sent automatically and cannot be disabled via configuration.

Steps to Reproduce

1. Set up automatic updates via a cron job that runs git pull && pip install -e . && hermes gateway restart periodically
2. Wait for an update to be applied
3. Observe the "Gateway shutting down" notification arriving on Telegram (or other platforms)

Expected Behavior

Either:

• A config option (e.g. gateway.notify_on_shutdown: false) to suppress the shutdown notification, or
• The shutdown message should include context about why the gateway is restarting (e.g. "Restarting to apply update X")

Actual Behavior

Users receive a generic "⚠️ Gateway shutting down" message with no context, no way to disable it, and no information about what triggered the restart.

Impact

With automatic updates every 30 minutes, users can receive many of these uninformative messages per day — pure noise with no actionable content.

Proposed Solution

Add a gateway.notify_on_shutdown config option (default: true for backward compatibility) that suppresses the shutdown notification when set to false. Optionally, allow passing a custom shutdown message so cron jobs can set context before restarting.

Environment

• OS: Linux (Proxmox LXC)
• Hermes: git install (~/.hermes/hermes-agent)
• Platform: Telegram