fix missing packages, remove dead code, replace ponymix with pactl

- Add wl-clipboard, libnotify, upower, bluez, bluez-utils to official.txt
- Remove stow (installed but never used)
- Remove dead moonlock.service cp block from post-install.sh
- Rewrite moonarch-sink-switcher and moonarch-volume to use pactl
  instead of ponymix (already available via libpulse)

scripts/post-install.sh

@@ -154,12 +154,6 @@ if [[ ! -f "$HOME/.zshrc" ]]; then
     echo "source /etc/zsh/zshrc.moonarch" >> "$HOME/.zshrc"
 fi
 
-# --- moonlock systemd user service ---
-
-log "Configuring moonlock user service..."
-sudo mkdir -p /etc/systemd/user
-sudo cp "$DEFAULTS_DIR/etc/systemd/user/moonlock.service" /etc/systemd/user/moonlock.service
-
 # --- greetd / moongreet configuration ---
 
 log "Configuring greetd + moongreet..."