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

bin/nomarchy-theme-set

@@ -32,6 +32,12 @@ fi
 TMP_JSON=$(mktemp)
 jq ".theme = \"$THEME_NAME\"" "$STATE_FILE" > "$TMP_JSON" && mv "$TMP_JSON" "$STATE_FILE"
 
+# Sync to system state if we have permissions (for system-level theming like browser policies)
+SYSTEM_STATE_FILE="/etc/nixos/state.json"
+if [ -w "$SYSTEM_STATE_FILE" ] || [ -w "/etc/nixos" ]; then
+    sudo jq ".theme = \"$THEME_NAME\"" "$SYSTEM_STATE_FILE" > /tmp/system-state.json 2>/dev/null && sudo mv /tmp/system-state.json "$SYSTEM_STATE_FILE" 2>/dev/null || true
+fi
+
 # Try to find a background for this theme
 BG_DIR="$THEMES_DIR/$THEME_NAME/backgrounds"
 if [ -d "$BG_DIR" ]; then