dev: NixOS 25.11 매뉴얼 로컬 사본 추가

nixpkgs nixos-25.11 브랜치의 nixos/doc/manual/ 디렉토리를 sparse clone으로
가져와 ~/obsidian/dev/nixos-manual/에 복사. _index.md에 구조/갱신 방법 정리.

오프라인 참조 + AI 에이전트 컨텍스트용. sandbox-tokyo 같은 NixOS 노드 운영 시
빠른 참조로 사용.

dev/nixos-manual/configuration/wayland.chapter.md

@@ -0,0 +1,24 @@
+# Wayland {#sec-wayland}
+
+While X11 (see [](#sec-x11)) is still the primary display technology
+on NixOS, Wayland support is steadily improving. Where X11 separates the
+X Server and the window manager, on Wayland those are combined: a
+Wayland Compositor is like an X11 window manager, but also embeds the
+Wayland 'Server' functionality. This means it is sufficient to install
+a Wayland Compositor such as sway without separately enabling a Wayland
+server:
+
+```nix
+{ programs.sway.enable = true; }
+```
+
+This installs the sway compositor along with some essential utilities.
+Now you can start sway from the TTY console.
+
+If you are using a wlroots-based compositor, like sway, and want to be
+able to share your screen, make sure to configure Pipewire using
+[](#opt-services.pipewire.enable)
+and related options.
+
+For more helpful tips and tricks, see the
+[wiki page about Sway](https://wiki.nixos.org/wiki/Sway).