refactor: 重构为三设备架构，zsh 迁移至 fish

- 新增 darwinConfigurations: mac-mini, macbook-air (aarch64-darwin)
- WSL 统一用户名为 imbytecat，主机名改为 awesome-* 系列
- zsh 全面迁移至 fish (abbrs, 内置补全/高亮, zoxide --cmd cd)
- 激活 nix-darwin 模块: Homebrew, 系统偏好, Touch ID sudo
- 移除 bare/standalone 配置及 catppuccin nixosModule from mkDarwin

modules/nixos/default.nix

@@ -8,12 +8,12 @@
   ];
 
   # ── Default shell ──────────────────────────────────
-  programs.zsh.enable = true;
+  programs.fish.enable = true;
 
   # ── Default user ───────────────────────────────────
   users.users.${username} = {
     isNormalUser = true;
-    shell = pkgs.zsh;
+    shell = pkgs.fish;
     extraGroups = [ "wheel" ];
   };