Refactor DMS configuration and introduce home-manager integration

- Simplified `default.nix` by removing legacy home-manager settings and delegating them to a new `_private/hm.nix` module for better organization.
- Added a new script `dms-restart-once.sh` to handle service restarts and cache management for DMS plugins.
- Updated the DMS configuration to streamline the integration of third-party plugins and improve overall modularity.

modules/desktop/shells/dms/default.nix

@@ -1,4 +1,4 @@
-{ inputs, ... }: {
+{ ... }: {
   flake.nixosModules.desktopShellDmsOptions = { lib, ... }: {
     options.chiasson.desktop.shells.dms = {
       enableGpuTemp = lib.mkOption {
@@ -45,29 +45,5 @@
     };
   };
 
-  flake.homeManagerModules.desktopShellDms = {
-    lib,
-    osConfig ? { },
-    ...
-  }:
-  let
-    cfg = lib.attrByPath [ "chiasson" "desktop" "shells" "dms" ] { } osConfig;
-    selectedShell = lib.attrByPath [ "chiasson" "desktop" "shell" ] null osConfig;
-    dmsEnabled = selectedShell == "dms";
-    hostName = lib.attrByPath [ "networking" "hostName" ] "nixos" osConfig;
-    rebuildCommand =
-      if (cfg.rebuildCommand or null) != null then
-        cfg.rebuildCommand
-      else
-        [ "sudo" "nixos-rebuild" "switch" "--flake" ".#${hostName}" ];
-  in
-  {
-    imports = [
-      ./home-manager/default.nix
-    ];
-
-    config = lib.mkIf dmsEnabled {
-      programs.nix-monitor.rebuildCommand = rebuildCommand;
-    };
-  };
+  flake.homeManagerModules.desktopShellDms = import ./_private/hm.nix;
 }