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>

hosts/nixos/hs/home.nix

@@ -0,0 +1,11 @@
+{ config, pkgs, ... }:
+
+{
+  imports = [
+    ../home-default.nix
+  ];
+
+  # hs-specific home configuration
+  # Example: Server-specific tools, monitoring utilities, etc.
+  
+}

hosts/nixos/hs/system.nix

@@ -1,7 +1,8 @@
-{ config, pkgs, ... }: {
+{ config, pkgs, home-manager, nixvim, claude-code, ... }: {
   imports = [
     ./hardware-configuration.nix
     ./disk-config.nix
+    home-manager.nixosModules.home-manager
   ];
 
   # GRUB bootloader with ZFS support
@@ -24,7 +25,7 @@
   # Network configuration
   networking = {
     hostName = "hs";
-    hostId = "12345678"; # Required for ZFS, good practice for any system
+    hostId = "8425e349"; # Required for ZFS, good practice for any system
     networkmanager.enable = true;
     firewall.enable = false;
     # firewall.allowedTCPPorts = [ 22 ]; # SSH
@@ -49,6 +50,12 @@
 
   # Define a user account
   users.users.root = {
+    # Clear any inherited password settings
+    hashedPassword = null;
+    hashedPasswordFile = null;
+    password = null;
+    initialHashedPassword = null;
+    initialPassword = null;
     openssh.authorizedKeys.keys = [
       "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIG35m0DgTrEOAM+1wAlYZ8mvLelNTcx65cFccGPQcxmo yanlin@imac"
     ];
@@ -110,6 +117,17 @@
     autodetect = true;
   };
 
+  # Allow unfree packages globally
+  nixpkgs.config.allowUnfree = true;
+
+  # Home Manager configuration
+  home-manager = {
+    useGlobalPkgs = true;
+    useUserPackages = true;
+    users.yanlin = import ./home.nix;
+    extraSpecialArgs = { inherit claude-code nixvim; };
+  };
+
   # This value determines the NixOS release from which the default
   # settings for stateful data, like file locations and database versions
   # on your system were taken. It's perfectly fine and recommended to leave