Initial commit: Busbar Designer

Web tool for designing nickel/copper busbars over cylindrical-cell battery
packs (21700, 18650) in hex holders. Flask + build123d backend exports
STEP/DXF/SVG; vanilla JS frontend with live preview, multi-project SQLite
persistence, snapshot history.

Deploy scripts in deploy/ (proxmox-lxc.sh, install.sh, update.sh).

deploy/update.sh

@@ -0,0 +1,45 @@
+#!/usr/bin/env bash
+# update.sh — pull the latest from the configured branch, refresh deps, restart.
+#
+# Optional env (override defaults set at install time):
+#   INSTALL_DIR  default /opt/busbar-designer
+#   SVC_USER     default busbar
+#   BRANCH       default main  (or whatever the local checkout tracks)
+
+set -euo pipefail
+
+INSTALL_DIR="${INSTALL_DIR:-/opt/busbar-designer}"
+SVC_USER="${SVC_USER:-busbar}"
+BRANCH="${BRANCH:-}"
+
+GREEN='\033[0;32m'; RED='\033[0;31m'; NC='\033[0m'
+log() { echo -e "${GREEN}▸${NC} $*"; }
+die() { echo -e "${RED}✗ $*${NC}" >&2; exit 1; }
+
+[[ $EUID -eq 0 ]] || die "Run as root."
+[[ -d "$INSTALL_DIR/.git" ]] || die "$INSTALL_DIR is not a git checkout."
+
+cd "$INSTALL_DIR"
+
+# Use the branch the working copy tracks if not overridden.
+if [[ -z "$BRANCH" ]]; then
+    BRANCH=$(sudo -u "$SVC_USER" git -C "$INSTALL_DIR" rev-parse --abbrev-ref HEAD)
+fi
+
+log "Pulling origin/$BRANCH..."
+sudo -u "$SVC_USER" git -C "$INSTALL_DIR" fetch --depth 1 origin "$BRANCH"
+sudo -u "$SVC_USER" git -C "$INSTALL_DIR" reset --hard "origin/$BRANCH"
+
+log "Refreshing Python deps..."
+sudo -u "$SVC_USER" "$INSTALL_DIR/.venv/bin/pip" install --quiet --upgrade \
+    -r "$INSTALL_DIR/requirements.txt" gunicorn
+
+log "Restarting busbar-designer..."
+systemctl restart busbar-designer
+sleep 2
+
+if systemctl is-active --quiet busbar-designer; then
+    log "✓ Updated and restarted."
+else
+    die "Service failed after restart. journalctl -u busbar-designer -n 50"
+fi