Expose Sentinel server metrics through the public API

[robertortorres]

Hi,

I've been working with the Coolify API for some internal automation and monitoring, and noticed that server CPU and memory metrics are already available in the UI through Sentinel, but there doesn't seem to be a public API endpoint to retrieve the same data.

I'd like to propose exposing these existing metrics through the API, something like:

GET /api/v1/servers/{uuid}/metrics?minutes=10

The idea is to reuse the existing metrics implementation rather than introduce another metrics collector or a separate data source.

The response could contain the CPU and memory history already collected by Sentinel:

{
"cpu": [
[timestamp, percentage]
],
"memory": [
[timestamp, percentage]
]
}

A few things I think would be important:

• Use the existing API authentication and team/server access controls.
• Require read permission.
• Allow selecting the history window with a minutes parameter.
• Respect the Sentinel metrics retention configured for that server.
• Return the same CPU and memory data that Coolify already uses internally for its metrics charts.
• Return null metrics when metrics are disabled for the server.

My main use case is external monitoring/automation where I want to consume Coolify's existing server metrics without having to access Sentinel directly or maintain a second monitoring path.

I've implemented and tested a small version of this locally to validate the approach, including authorization, team isolation, input validation, Sentinel retention limits, and CPU/memory history retrieval.

Before opening a PR, I'd like to check whether exposing the existing Sentinel metrics this way fits the direction of the public API, and whether there is a preferred response format or endpoint structure.

Thanks!