Add NixOS home manager config and fix flake warnings

- Add hosts/nixos/home-default.nix with nvim, ssh, and other modules
- Add hosts/nixos/hs/home.nix importing home-default
- Fix nixpkgs.config conflict by moving allowUnfree to system level
- Fix root user password conflicts by explicitly clearing all options
- Add home-manager integration to hs system configuration
- Update hostId from placeholder to actual value (8425e349)
- Add claude-code support for x86_64-linux architecture

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

flake.nix

@@ -42,6 +42,7 @@
         ./hosts/nixos/hs/system.nix
         ./hosts/nixos/hs/disk-config.nix
       ];
+      specialArgs = { inherit home-manager nixvim claude-code; };
     };
 
     nixosConfigurations."hs-iso" = nixpkgs.lib.nixosSystem {
@@ -64,6 +65,12 @@
         modules = [ ./hosts/darwin/mba/home.nix ];
         extraSpecialArgs = { inherit claude-code nixvim firefox-addons; };
       };
+
+      "yanlin@hs" = home-manager.lib.homeManagerConfiguration {
+        pkgs = nixpkgs.legacyPackages.x86_64-linux;
+        modules = [ ./hosts/nixos/hs/home.nix ];
+        extraSpecialArgs = { inherit claude-code nixvim; };
+      };
     };
   };
 }