chore(hygiene): final script cleanup and plymouth optimization

- Remove unused pkg and cmd helper scripts
- Optimize Plymouth settings for cleaner boot in all environments
- Skip hardware auto-detection logic in Live ISO environment

bin/nomarchy-on-boot

@@ -21,6 +21,11 @@ fi
 # 3. Declarative hardware configuration check (nixos-hardware)
 # This part ensures that if we are on an installed system, the correct
 # nixos-hardware module is selected in the configuration.
+# Skip this in the Live ISO environment
+if [[ $USER == "nixos" ]] || [[ -f /etc/nixos/hosts/live-iso.nix ]]; then
+    exit 0
+fi
+
 HW_FILE="/etc/nixos/hardware-selection.nix"
 if [ -w "$HW_FILE" ]; then
     PRODUCT_NAME=$(cat /sys/class/dmi/id/product_name 2>/dev/null || echo "Unknown")