compositor+matugen: border override, hypr/mango layout overrides, new

templates, respect XDG paths
- Add Hyprland and MangoWC templates
- Add GUI gaps, window radius, and border thickness overrides for niri,
  Hyprland, and MangoWC
- Add replacement support in matugen templates for DATA_DIR, CACHE_DIR,
  CONFIG_DIR
fixes #1274
fixes #1273

core/internal/config/embedded/niri.kdl

@@ -240,10 +240,6 @@ window-rule {
     match app-id="kitty"
     draw-border-with-background false
 }
-window-rule {
-    match is-active=false
-    opacity 0.9
-}
 window-rule {
     match app-id=r#"firefox$"# title="^Picture-in-Picture$"
     match app-id="zoom"
@@ -273,3 +269,4 @@ include "dms/colors.kdl"
 include "dms/layout.kdl"
 include "dms/alttab.kdl"
 include "dms/binds.kdl"
+include "dms/outputs.kdl"