Description of Changes

Enable notifier module, and re-enable exec module on host only. The latter still enables RCE from anywhere
to the host, which needs to be fixed.

The notifier runs a socket-activated user service that can receive and display notifications for
logged in users from any VM or host via givc-cli. This can be used standalone, or in conjunction
with a notification proxy for generic forwarding. Alternatively, the latter can be achieved by
connecting dbus user sessions.

Example (e.g. from admin-vm):

<givc-cli> <args> notify-user gui-vm --event "vm-alert" --title 'VM Test Alert' --urgency 'critical' --message "This is a VM test notification"

Type of Change

• New Feature
• Bug Fix
• Improvement / Refactor

Related Issues / Tickets

Checklist

• Clear summary in PR description
• Detailed and meaningful commit message(s)
• Commits are logically organized and squashed if appropriate
• Contribution guidelines followed
• Ghaf documentation updated with the commit - https://tiiuae.github.io/ghaf/
• Author has run make-checks and it passes
• All automatic GitHub Action checks pass - see actions
• Author has added reviewers and removed PR draft status

Testing Instructions

Applicable Targets

• Orin AGX aarch64
• Orin NX aarch64
• Lenovo X1 x86_64
• Dell Latitude x86_64
• System 76 x86_64

Installation Method

• Requires full re-installation
• Can be updated with nixos-rebuild ... switch
• Other:

Test Steps To Verify:

1. ...