Switch from pop-os iced fork to iced_layershell

[MalpenZibo]

Summary

• Replace the pop-os iced fork (MalpenZibo/iced) with iced_layershell, a standalone Wayland layer shell backend built on standard iced 0.14
• Migrate all iced:: imports to iced_layershell::, replacing iced::window::Id with SurfaceId, iced::daemon() with iced_layershell::application(), and platform-specific layer surface APIs with iced_layershell equivalents
• Merge PulseAudio listener and commander into a single connection thread to avoid mainloop assertion failures under the calloop-based event loop

Test plan

• Bar renders correctly on single and multi-monitor setups
• ESC key closes menus
• Audio controls work (volume slider, mute toggle, device switching)
• SIGUSR1 visibility toggle works
• Output add/remove events handled correctly

[romanstingler]

Background color is missing.

[appearance]
style = "Solid"
success_color = "#a3be8c"
text_color = "#eceff4"
workspace_colors = ["#88c0d0", "#81a1c1", "#5e81ac"]

[appearance.primary_color]
base = "#88c0d0"
text = "#242933"

[appearance.danger_color]
base = "#bf616a"
weak = "#ebcb8b"

[appearance.background_color]
base = "#3b4252"
weak = "#2e3440"
strong = "#3b4252"

[appearance.secondary_color]
base = "#1c212b"
strong = "#2e3440"

[MalpenZibo]

Can you share your appearance settings? This could be related to the changes to the theme settings. I want to fix that kind of stuff in a dedicated PR. Maybe if we decide to stick with this iced_layershell solution, I can rebase #574 on top of this

[romanstingler]

I think I found it.

[MalpenZibo]

Ok secondary color will be probably deprecated.
In the refactor palette PR I plan to resolve some of this kind of issue. I will use you configuration to make some test!