feat: Add machinectl management and backup/restore system

- Create cfg/aios-ctl.zsh with machinectl control commands
  - aios-start/stop/shell/login for basic operations
  - aios-backup to save current state to aiosback
  - aios-reset to restore from backup (preserves config files)
  - aios-update to update packages in backup
- Create cfg/install.sh for automated installation
  - Extracts tarball to /var/lib/machines/aios
  - Creates systemd-nspawn configuration
  - Automatically creates initial backup image (aiosback)
- Include aios-ctl.zsh in container at /opt/aios-ctl.zsh
- Include install.sh in tarball for easy deployment
- Config files in ~/.config/syui/ai are bind-mounted and preserved across resets

cfg/install.sh

@@ -0,0 +1,82 @@
+#!/bin/bash
+# aios installation script
+
+set -e
+
+NAME="aios"
+BACKUP="${NAME}back"
+TARBALL="aios-bootstrap.tar.gz"
+
+echo "=== aios installation ==="
+echo ""
+
+# Check if running as root
+if [ "$EUID" -ne 0 ]; then
+    echo "Error: This script must be run as root"
+    exit 1
+fi
+
+# Check if tarball exists
+if [ ! -f "$TARBALL" ]; then
+    echo "Error: $TARBALL not found"
+    echo "Please download aios-bootstrap.tar.gz first"
+    exit 1
+fi
+
+# Extract tarball
+echo "1. Extracting $TARBALL..."
+tar xf "$TARBALL"
+
+# Move to /var/lib/machines/
+echo "2. Installing to /var/lib/machines/$NAME..."
+rm -rf /var/lib/machines/$NAME
+mkdir -p /var/lib/machines
+mv root.x86_64/var/lib/machines/arch /var/lib/machines/$NAME
+
+# Copy nspawn configuration
+echo "3. Installing systemd-nspawn configuration..."
+mkdir -p /etc/systemd/nspawn
+cat > /etc/systemd/nspawn/$NAME.nspawn <<'EOF'
+[Exec]
+Boot=yes
+PrivateUsers=pick
+ResolvConf=copy-host
+
+[Files]
+Bind=%h/.config/syui/ai:/root/.config/syui/ai
+
+[Network]
+Private=yes
+VirtualEthernet=yes
+EOF
+
+# Enable systemd-machined
+echo "4. Enabling systemd-machined..."
+systemctl enable --now systemd-machined
+
+# Create initial backup
+echo "5. Creating initial backup image..."
+machinectl clone $NAME $BACKUP
+
+echo ""
+echo "=== Installation complete ==="
+echo ""
+echo "Next steps for each user:"
+echo "  1. Copy control script to your home:"
+echo "     cp /var/lib/machines/$NAME/opt/aios-ctl.zsh ~/.aios-ctl.zsh"
+echo ""
+echo "  2. Add to your .zshrc:"
+echo "     echo 'source ~/.aios-ctl.zsh' >> ~/.zshrc"
+echo "     source ~/.zshrc"
+echo ""
+echo "  3. Start aios:"
+echo "     aios-start"
+echo ""
+echo "  4. Login to aios:"
+echo "     aios-login"
+echo ""
+echo "Available commands:"
+echo "  aios-start, aios-stop, aios-shell, aios-login"
+echo "  aios-backup, aios-reset, aios-update"
+echo "  aios-help for full list"
+echo ""