新增 niri/dms/gtk/qt/cava/fcitx5 等配置并添加 .gitignore

- 纳入版本管理: niri/(含 dms/), DankMaterialShell/, environment.d/,
  cava/, gtk-3.0/, gtk-4.0/, qt5ct/, qt6ct/, fcitx5/
- 新增 .gitignore: 排除 *.bak/*.backup*、fcitx5/conf/cached_layouts、
  DankMaterialShell 运行时标志
- 同步已有的 kitty/nvim/.zshrc 修改

niri/dms/layout.kdl

@@ -0,0 +1,22 @@
+// ! DO NOT EDIT !
+        // ! AUTO-GENERATED BY DMS !
+        // ! CHANGES WILL BE OVERWRITTEN !
+        // ! PLACE YOUR CUSTOM CONFIGURATION ELSEWHERE !
+
+        layout {
+        gaps 4
+
+        border {
+        width 2
+        }
+
+        focus-ring {
+        width 2
+        }
+        }
+        window-rule {
+        geometry-corner-radius 12
+        clip-to-geometry true
+        tiled-state true
+        draw-border-with-background false
+        }