Pin linux-zen kernel in archinstall config, add quiet boot param

- Set kernels to linux-zen in user_configuration.json to skip
  interactive kernel selection during install
- Add post-install step to append quiet to non-fallback systemd-boot
  entries for clean boot output

config/user_configuration.json

@@ -8,6 +8,8 @@
 
     "bootloader": "Systemd-boot",
 
+    "kernels": ["linux-zen"],
+
     "hostname": "moonarch",
 
     "locale_config": {

scripts/post-install.sh

@@ -154,6 +154,16 @@ sudo ufw default deny incoming
 sudo ufw default allow outgoing
 sudo ufw --force enable
 
+# --- Boot parameters: add quiet to systemd-boot entries ---
+
+log "Configuring boot parameters..."
+for entry in /boot/loader/entries/*.conf; do
+    if [[ -f "$entry" ]] && [[ "$(basename "$entry")" != *fallback* ]] && ! grep -q 'quiet' "$entry"; then
+        sudo sed -i '/^options/ s/$/ quiet/' "$entry"
+        log "  + $(basename "$entry") — quiet added"
+    fi
+done
+
 # --- Docker-Gruppe ---
 
 if ! groups | grep -q docker; then