added mangowc to uwsm

# Add mangowc (mango) compositor support ## Summary This PR adds support for the mangowc Wayland compositor (binary: `mango`) to uwsm. ## Changes - Added `uwsm-plugins/mango.sh` plugin with compositor-specific quirks - Updated `uwsm-plugins/meson.build` to include the new plugin ## Plugin Features The `mango.sh` plugin implements: - **XWayland detection**: Checks `~/.config/mango/config.conf` for xwayland disable directive - **XDG_CURRENT_DESKTOP**: Automatically appends `wlroots` to desktop names (mangowc is wlroots-based) - **Environment variables**: Exports `XCURSOR_SIZE` and `XCURSOR_THEME` to systemd/dbus activation environments ## Usage ```bash uwsm start mango ``` Or with a desktop entry in `~/.local/share/wayland-sessions/mango.desktop`: ```ini [Desktop Entry] Name=Mango Comment=Mango Wayland Compositor Exec=mango DesktopNames=mango;wlroots Type=Application ``` ## Benefits - Proper systemd session integration - Automatic startup of services in `graphical-session.target.wants` - XDG portal support (xdg-desktop-portal-gtk, xdg-desktop-portal-wlr, etc.) - Clean session lifecycle management ## Testing Tested on: - Distribution: Arch Linux - mangowc version: Unknown (development build) - Status: Plugin implemented but graphical session startup requires further testing ## Related - mangowc project: https://github.com/DreamMaoMao/mangowc ## Notes This is an initial implementation. Further testing and refinement may be needed to ensure full compatibility with mangowc's specific requirements.