refactor: remove redundant aliases, comments, and fix lazygit pager config

modules/nixos/default.nix

@@ -10,21 +10,18 @@
     ./docker.nix
   ];
 
-  # ── System-essential packages ──────────────────────
   environment.systemPackages = with pkgs; [
     curl
     git
     ghostty.terminfo
   ];
 
-  # ── Locale / Timezone ──────────────────────────────
   i18n = {
     defaultLocale = "en_US.UTF-8";
     supportedLocales = [ "en_US.UTF-8/UTF-8" ];
   };
   time.timeZone = "Asia/Shanghai";
 
-  # ── Default user ───────────────────────────────────
   users.users.${username} = {
     isNormalUser = true;
     shell = pkgs.fish;
@@ -32,6 +29,5 @@
     openssh.authorizedKeys.keys = sshKeys;
   };
 
-  # ── sudo ───────────────────────────────────────────
   security.sudo.wheelNeedsPassword = false;
 }