Revert: Restore Boot=yes and machinectl start workspace

- Restore Boot=yes in workspace.nspawn
- Restore machinectl start workspace in .zshrc
- Boot method is necessary for proper systemd environment

cfg/setup-user.sh

@@ -35,6 +35,7 @@ echo "Creating workspace container configuration..."
 mkdir -p $ROOTFS/etc/systemd/nspawn
 cat > $ROOTFS/etc/systemd/nspawn/workspace.nspawn <<'EOF'
 [Exec]
+Boot=yes
 ResolvConf=copy-host
 
 [Files]
@@ -75,7 +76,9 @@ if [[ -o login ]] && [[ -o interactive ]]; then
     if [[ -z "$INSIDE_WORKSPACE" ]]; then
         # Running as ai user on aios OS - enter workspace container
         export INSIDE_WORKSPACE=1
-        exec sudo systemd-nspawn -q -D /var/lib/machines/workspace /bin/zsh
+        sudo machinectl start workspace 2>/dev/null || true
+        sleep 1
+        exec sudo machinectl shell workspace
     else
         # Running as root inside workspace container - start claude
         if command -v claude &>/dev/null; then