feat(mango): first-class MangoWM support across DMS, dankinstaller & UI tools

- Bring up Mango to parity with niri/hyprland via a native JSON-IPC w/Native MangoServic., replaces the legacy dwl/`mmsg` path and recent breaking changes
- Dankinstall: mango supported installer, config/binds templates, and packaging (Arch AUR, Fedora Terra auto-enable, Gentoo GURU)
- Window rules: Go provider + CLI + Settings GUI editor
- Keybinds + config reload on edit (mmsg dispatch reload_config)
- Misc new supported options in DMS settings

quickshell/Services/SessionService.qml

@@ -319,6 +319,11 @@ Singleton {
                 return;
             }
 
+            if (CompositorService.isMango) {
+                MangoService.quit();
+                return;
+            }
+
             if (CompositorService.isLabwc) {
                 LabwcService.quit();
                 return;