feat(systemModules:host): add initial host configuration module

used to define general host configuration, including:

- hardware
- name
- admin
- type
- role

system/modules/host/hardware/features/ssd/default.nix

@@ -0,0 +1,23 @@
+{ lib, config, ... }:
+
+let
+  features = config.systemModules.host.hardware.ssd;
+  inherit (lib) mkIf;
+  inherit (builtins) elem;
+in
+
+{
+  config = mkIf (elem "ssd" features) {
+    services.fstrim = {
+      enable = true;
+    };
+    # only run fstrim while connected on AC
+    systemd.services.fstrim = {
+      unitConfig.ConditionACPower = true;
+      serviceConfig = {
+        Nice = 19;
+        IOSchedulingClass = "idle";
+      };
+    }; 
+  };
+}