feat: 集成 sops-nix 机密管理，声明式注入 Fish 环境变量

home/default.nix

@@ -12,12 +12,12 @@
     ./shell
     ./dev
     ./theme.nix
+    ./secrets.nix
   ];
 
   home = {
     username = username;
-    homeDirectory =
-      if pkgs.stdenv.isDarwin then "/Users/${username}" else "/home/${username}";
+    homeDirectory = if pkgs.stdenv.isDarwin then "/Users/${username}" else "/home/${username}";
     stateVersion = "24.11";
   };
 
@@ -45,6 +45,10 @@
     nvd # nix version diff
     nh # nix helper
 
+    # Secrets management
+    sops
+    age
+
     # AI coding agent
     opencode
     comment-checker