Replace qterminal with xterm for reliable arrow key support

qterminal produces escape characters for arrow keys in VNC. xterm handles
this correctly. Also make brew shellenv conditional to suppress errors
when brew isn't installed yet.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

setup-openclaw-lxc.sh

@@ -195,7 +195,7 @@ ct_exec "
     su - brewuser -c 'NONINTERACTIVE=1 /bin/bash -c \"\$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)\"' 2>&1 | tail -5
 
     # Make brew available system-wide for root
-    echo 'eval \"\$(/home/linuxbrew/.linuxbrew/bin/brew shellenv)\"' >> /root/.bashrc
+    echo '[ -x /home/linuxbrew/.linuxbrew/bin/brew ] && eval \"\$(/home/linuxbrew/.linuxbrew/bin/brew shellenv)\"' >> /root/.bashrc
     ln -sf /home/linuxbrew/.linuxbrew/bin/brew /usr/local/bin/brew
 "
 ok "Homebrew installed."
@@ -208,7 +208,7 @@ info "Installing LXQt, TigerVNC, noVNC (this takes a few minutes)..."
 ct_exec "
     export DEBIAN_FRONTEND=noninteractive
     export LANG=en_US.UTF-8 LC_ALL=en_US.UTF-8
-    apt-get install -y lxqt openbox qterminal tigervnc-standalone-server novnc websockify dbus-x11 fonts-noto-color-emoji 2>&1 \
+    apt-get install -y lxqt openbox xterm tigervnc-standalone-server novnc websockify dbus-x11 fonts-noto-color-emoji 2>&1 \
         | grep -v -E 'Failed to write|Failed to send reload|Permission denied|Cannot set LC_'
 "
 ok "Desktop environment installed."
@@ -314,7 +314,7 @@ Version=1.0
 Type=Application
 Name=OpenClaw Setup Wizard
 Comment=Run the OpenClaw onboarding wizard to configure your AI assistant
-Exec=qterminal --title 'OpenClaw Onboarding' -e sh -c 'openclaw onboard; exec bash'
+Exec=xterm -title 'OpenClaw Onboarding' -fa 'Monospace' -fs 12 -e sh -c 'openclaw onboard; exec bash'
 Icon=utilities-terminal
 Terminal=false
 Categories=Utility;