Add nightly auto-update via systemd timer

Add scripts/update.sh that fetches origin/main, resets if changed,
reinstalls dependencies when requirements.txt differs, and restarts
the service. Deploy script now installs a systemd timer that triggers
the update nightly at 03:00 with Persistent=true for catch-up on
missed runs.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

scripts/deploy.sh

@@ -19,12 +19,12 @@ if [[ ! -f /proc/device-tree/model ]] || ! grep -q "Raspberry Pi" /proc/device-t
 fi
 
 # Step 1: Install system dependencies
-echo "[1/4] Installing system dependencies..."
+echo "[1/6] Installing system dependencies..."
 sudo apt update
 sudo apt install -y python3 python3-pip python3-venv libusb-1.0-0-dev
 
 # Step 2: Install uv if not present
-echo "[2/4] Setting up Python package manager..."
+echo "[2/6] Setting up Python package manager..."
 if ! command -v uv &> /dev/null; then
     echo "Installing uv..."
     curl -LsSf https://astral.sh/uv/install.sh | sh
@@ -32,13 +32,13 @@ if ! command -v uv &> /dev/null; then
 fi
 
 # Step 3: Setup Python environment
-echo "[3/4] Installing Python dependencies..."
+echo "[3/6] Installing Python dependencies..."
 cd "$PROJECT_DIR"
 uv venv
 uv pip install -r requirements.txt
 
 # Step 4: Setup udev rules
-echo "[4/4] Configuring USB permissions..."
+echo "[4/6] Configuring USB permissions..."
 if [[ ! -f /etc/udev/rules.d/99-brother-ql.rules ]]; then
     sudo tee /etc/udev/rules.d/99-brother-ql.rules > /dev/null << 'EOF'
 # Brother QL label printers
@@ -73,6 +73,37 @@ EOF
 sudo systemctl daemon-reload
 sudo systemctl enable brother-ql-bridge
 
+# Step 6: Install nightly update timer
+echo "[5/6] Installing nightly update timer..."
+chmod +x "$PROJECT_DIR/scripts/update.sh"
+
+sudo tee /etc/systemd/system/brother-ql-bridge-update.service > /dev/null << EOF
+[Unit]
+Description=Update Brother QL Bridge from GitHub
+
+[Service]
+Type=oneshot
+User=$USER
+WorkingDirectory=$PROJECT_DIR
+ExecStart=$PROJECT_DIR/scripts/update.sh
+EOF
+
+sudo tee /etc/systemd/system/brother-ql-bridge-update.timer > /dev/null << 'EOF'
+[Unit]
+Description=Nightly update for Brother QL Bridge
+
+[Timer]
+OnCalendar=*-*-* 03:00:00
+Persistent=true
+
+[Install]
+WantedBy=timers.target
+EOF
+
+echo "[6/6] Enabling update timer..."
+sudo systemctl daemon-reload
+sudo systemctl enable --now brother-ql-bridge-update.timer
+
 echo ""
 echo "=== Deployment Complete ==="
 echo ""