Suggestion -> System Performance Metrics in AdGuard Home

### Prerequisites

- [x] I have checked the [Wiki](https://github.com/AdguardTeam/AdGuardHome/wiki) and [Discussions](https://github.com/AdguardTeam/AdGuardHome/discussions) and found no answer

- [x] I have searched other issues and found no duplicates

- [x] I want to request a feature or enhancement and not ask a question

### The problem

First off, I want to thank you for creating such an excellent and user-friendly tool with AdGuard Home. As a long-time (7+ years) user of Pi-hole, I made the switch to AdGuard Home and have been thoroughly impressed by its simplicity, effectiveness, and reliability. It’s clear that you’ve put thought into making it accessible while delivering a high-performance experience.

That said, I’d like to suggest a potential feature that I believe many users, including myself, would find incredibly useful. It would be fantastic if the dashboard included some basic system monitoring stats, such as CPU usage, memory utilization, and device temperature. For those of us running AdGuard Home on devices like Raspberry Pis, having this information readily available at a glance would make it much easier to ensure everything is running smoothly without needing to rely on external tools.

I really appreciate how responsive you are to user feedback, which is part of why I’ve grown to trust and enjoy using AdGuard Home as well as your other products on my iDevices. I hope this idea resonates, and I’d be thrilled to see it implemented in the future!

Thank you again for your hard work and dedication.

### Proposed solution

Display CPU, Memory, and Temp on Dashboard.

### Alternatives considered and additional information

NA