refactor: Simplify install.sh and rename arch to aios throughout

- Simplified install.sh to just extract and mv
- Renamed root.x86_64/var/lib/machines/arch to aios
- Updated all references in build.zsh, setup-user.sh, setup-claude.sh

cfg/install.sh

@@ -1,81 +1,19 @@
 #!/bin/bash
 # aios installation script
 
-set -e
-
 NAME="aios"
 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 $TARBALL..."
+# Extract and install
 tar xf "$TARBALL"
-
-# Install aios (base container)
-echo "2. Installing aios to /var/lib/machines/..."
-rm -rf /var/lib/machines/$NAME
 mkdir -p /var/lib/machines
-mv root.x86_64/var/lib/machines/arch /var/lib/machines/$NAME
+mv root.x86_64/var/lib/machines/aios /var/lib/machines/$NAME
 
-# Copy nspawn configuration
-echo "3. Installing systemd-nspawn configuration..."
-mkdir -p /etc/systemd/nspawn
-
-# Create aios.nspawn (only one container needed)
-cat > /etc/systemd/nspawn/$NAME.nspawn <<'EOF'
-[Exec]
-Boot=yes
-PrivateUsers=pick
-ResolvConf=copy-host
-
-[Files]
-Bind=/root/.config/syui/ai:/root/.config/syui/ai
-
-[Network]
-VirtualEthernet=no
-EOF
-
-# Create bind mount directory
-mkdir -p /root/.config/syui/ai
-
-# Enable systemd-machined
-echo "4. Enabling systemd-machined..."
-systemctl enable --now systemd-machined
-
-echo ""
 echo "=== Installation complete ==="
 echo ""
-echo "Next steps for each user:"
-echo "  1. Copy control script to your home:"
-echo "     cp /var/lib/machines/$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 "Usage:"
+echo "  sudo machinectl start $NAME"
+echo "  sudo machinectl shell $NAME /bin/su - ai"
 echo ""