feat: 启用窗口规则与布局子配置

- config.kdl 末尾引入 dms/windowrules.kdl 与 dms/layout.kdl
- windowrules.kdl: Thunderbird、kuro 默认浮动并固定尺寸，DMS 面板浮动

dms/windowrules.kdl

@@ -0,0 +1,24 @@
+// DMS Window Rules - Managed by DankMaterialShell
+// Do not edit manually - changes may be overwritten
+
+// @id=wr_1781421586006984518 @name=org.mozilla.Thunderbird
+window-rule {
+    match app-id="^org.mozilla.Thunderbird$"
+    open-floating true
+    default-column-width { fixed 1600; }
+    default-window-height { fixed 1200; }
+}
+
+// @id=wr_1783662328837880577 @name=kuro
+window-rule {
+    match app-id="^kuro$"
+    open-floating true
+    default-column-width { fixed 1280; }
+    default-window-height { fixed 1024; }
+}
+
+// @id=dms-floating-windows @name=DMS Floating Windows
+window-rule {
+    match app-id="^com.danklinux.dms$"
+    open-floating true
+}