WM (Linux): supports Umbriel version detection

[oldirtty]

Summary

Adds version detection support for the Umbriel Wayland compositor, part of the Noctalia ecosystem. Fastfetch already detects the compositor's process name (umbriel) via its generic Wayland detection, but {version} came back empty since no parser existed for it.

Related issue (required for new logos for new distros)

• Closes [FEAT] Add version detection for Umbriel window manager #2570

Changes

• Adds getUmbriel() in src/detection/wm/wm_linux.c, following the same pattern used for niri: runs umbriel --version, which outputs umbriel 0.1.0 (7a448abe550e), and extracts the version by cutting after the first space and before the last (.
• Registers umbriel in the ffDetectWMVersion dispatch, alongside the other Wayland compositors.

Full --format json output for the WM module:

{
  "type": "WM",
  "result": {
    "processName": "umbriel",
    "prettyName": "umbriel",
    "protocolName": "Wayland",
    "pluginName": "",
    "version": "0.1.0"
  }
}

Checklist

• I have tested my changes locally.

Screenshots

N/A

Checklist

• I have tested my changes locally.