feat(wlr/taskbar): add active-last option

[rawalrauf]

This PR adds a new configuration option active-last to the wlr/taskbar module, which moves the currently active window to the last (rightmost) position in the taskbar.

Motivation

The existing active-first option moves the active window to the first position, but there was no equivalent option to move it to the last position. This feature provides symmetry and gives users more flexibility in organizing their taskbar layout.

Changes

• Added active-last boolean option to wlr/taskbar module
• Updated man page documentation for waybar-wlr-taskbar.5.scd
• Implementation mirrors the existing active-first logic

Usage

json
"wlr/taskbar": {
"active-last": true
}

Notes

• active-first and active-last are mutually exclusive (only one should be used at a time)
• Uses GTK's move_button(button, -1) to move to the last position
• Minimal code change (3 lines in taskbar.cpp)

Testing

Tested on Arch Linux with Hyprland. The active window icon correctly moves to the rightmost position when switching between applications.