Process names and panel values invisible with Tokyo Night theme

First of all, thank you for this very useful and beautifully designed plugin! I really appreciate the work you’ve put into it.

## Issue

Process names, CPU percentages,..., are invisible with the Tokyo Night theme.

## Environment

- Omarchy: 4.0.1-1
- Theme: Tokyo Night
- Plugin revision: b4b5cc6

## Steps to reproduce

1. Use the Tokyo Night theme.
2. Open the CPU panel.

## Cause

`Panel.qml` uses `root.barForeground` for panel content. This is the adaptive
bar foreground and can be dark depending on the bar/background configuration,
even though the popup itself has a dark background.

## Tested fix

Using the popup palette fixes the issue:

```qml
readonly property color panelForeground: Color.popups.text

Then replace panel-content uses of root.barForeground with
root.panelForeground.

This also fixes the graph grid, process names, CPU percentages, temperature,
legend labels, load values, uptime, CPU count, and footer text.

Thank you!

Start with Panel.qml and inspect the panel-content color bindings, especially uses of root.barForeground. Verify the change with the Tokyo Night theme by opening the CPU panel; done means process names, values, graph labels, and footer text are visible.

Written by the indexing model from the issue text.