fix: 修复 nix flake check 和 build 错误

- 添加 system.primaryUser (nix-darwin 新要求)
- 全局应用 overlays 解决 comment-checker 找不到的问题
- git/ssh/delta 选项迁移到 home-manager 新 API
- 包改名: dockerfile-language-server, nixfmt, nixd
- neovim withRuby=false, catppuccin homeModules 更名
- 更新 flake.lock (nixpkgs, home-manager, catppuccin)

flake.lock

@@ -43,11 +43,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1775143651,
-        "narHash": "sha256-S0RqAyDPMTcv9vASMaE8eY1QexFysAOdnxUxFHIPOyE=",
+        "lastModified": 1775781825,
+        "narHash": "sha256-L5yKTpR+alrZU2XYYvIxCeCP4LBHU5jhwSj7H1VAavg=",
         "owner": "nix-community",
         "repo": "home-manager",
-        "rev": "d166a078541982a76f14d3e06e9665fa5c9ed85e",
+        "rev": "e35c39fca04fee829cecdf839a50eb9b54d8a701",
         "type": "github"
       },
       "original": {
@@ -99,11 +99,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1775036866,
-        "narHash": "sha256-ZojAnPuCdy657PbTq5V0Y+AHKhZAIwSIT2cb8UgAz/U=",
+        "lastModified": 1775710090,
+        "narHash": "sha256-ar3rofg+awPB8QXDaFJhJ2jJhu+KqN/PRCXeyuXR76E=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "6201e203d09599479a3b3450ed24fa81537ebc4e",
+        "rev": "4c1018dae018162ec878d42fec712642d214fdfa",
         "type": "github"
       },
       "original": {