feat: add Proxmox LXC deployment files

- Add deploy/proxmox-lxc-setup.sh to configure the frontend inside a Debian/Ubuntu LXC.
- Add deploy/thermopro-frontend.service systemd unit.
- Add deploy/README.md with Proxmox CT creation, file transfer, setup, proxy, and update steps.
- Update frontend README.md to point to the deployment guide.

frontend/deploy/proxmox-lxc-setup.sh

@@ -0,0 +1,64 @@
+#!/usr/bin/env bash
+# Run this script inside a freshly created Proxmox LXC container
+# (Debian 12 or Ubuntu 22.04/24.04) to install and configure the
+# ThermoPro CYD frontend.
+
+set -euo pipefail
+
+INSTALL_DIR="/opt/thermopro-frontend"
+DATA_DIR="/data"
+SERVICE_NAME="thermopro-frontend"
+
+if [[ $EUID -ne 0 ]]; then
+   echo "This script must be run as root (e.g. inside the LXC container)" >&2
+   exit 1
+fi
+
+echo "=== Updating packages ==="
+apt-get update
+apt-get upgrade -y
+
+echo "=== Installing Python tooling ==="
+apt-get install -y python3 python3-pip git curl
+
+echo "=== Creating application user ==="
+useradd -r -s /bin/false -d "${INSTALL_DIR}" thermopro || true
+
+echo "=== Creating data directory ==="
+mkdir -p "${DATA_DIR}"
+chown thermopro:thermopro "${DATA_DIR}"
+
+if [[ ! -d "${INSTALL_DIR}" ]]; then
+    echo "ERROR: ${INSTALL_DIR} does not exist."
+    echo "Copy the frontend/ folder into the container at ${INSTALL_DIR} first."
+    echo "Example from Proxmox host:"
+    echo "  pct push <ctid> /path/to/frontend.tar.gz /tmp/frontend.tar.gz"
+    echo "  pct exec <ctid> -- tar -xzf /tmp/frontend.tar.gz -C /opt"
+    exit 1
+fi
+
+cd "${INSTALL_DIR}"
+
+echo "=== Installing Python dependencies into vendor/ ==="
+pip3 install --target vendor --upgrade -r requirements.txt
+
+echo "=== Setting ownership ==="
+chown -R thermopro:thermopro "${INSTALL_DIR}"
+
+echo "=== Installing systemd service ==="
+cp "${INSTALL_DIR}/deploy/thermopro-frontend.service" /etc/systemd/system/
+systemctl daemon-reload
+systemctl enable "${SERVICE_NAME}"
+systemctl start "${SERVICE_NAME}"
+
+echo "=== Waiting for service to start ==="
+sleep 2
+systemctl status "${SERVICE_NAME}" --no-pager
+
+echo ""
+echo "=== Installation complete ==="
+echo "The frontend should now be running on http://<container-ip>:5000"
+echo ""
+echo "To check logs:   journalctl -u ${SERVICE_NAME} -f"
+echo "To edit config: nano /etc/systemd/system/${SERVICE_NAME}.service"
+echo "Then reload:    systemctl daemon-reload && systemctl restart ${SERVICE_NAME}"