feat(system): professionalize system configurations

- Consolidate imperative system settings into /etc/nixos/state.json
- Implement nomarchy.system options for DNS, Wifi powersave, Timezone, and hardware features
- Add declarative browser policies for Chromium/Brave based on theme
- Update toggles scripts to mutate system JSON and run sys-update --impure
- Remove obsolete imperative browser theme and redundant system modules

modules/system/state.nix

@@ -0,0 +1,28 @@
+{ lib, ... }:
+
+let
+  stateFile = "/etc/nixos/state.json";
+  
+  # Helper to read state from a file, with a default
+  readState = file: default:
+    if builtins.pathExists file then
+      builtins.fromJSON (builtins.readFile file)
+    else
+      default;
+
+  systemState = readState stateFile {};
+in
+{
+  config.nomarchy.system = {
+    dns = systemState.dns or "DHCP";
+    customDns = systemState.customDns or [];
+    wifi.powersave = systemState.wifi.powersave or true;
+    timezone = systemState.timezone or "UTC";
+    features = {
+      fingerprint = systemState.features.fingerprint or false;
+      fido2 = systemState.features.fido2 or false;
+      hybridGPU = systemState.features.hybridGPU or false;
+    };
+    theme = systemState.theme or "nord";
+  };
+}