fix(deploy): add safe deploy script to preserve data/

Previous deploy used git stash -u which deleted untracked data/*.json
files (servers, synology, ha, pc). New script backs up and restores them.

Co-authored-by: Cursor <cursoragent@cursor.com>

scripts/deploy.sh

@@ -0,0 +1,39 @@
+#!/bin/bash
+# Safe deploy: preserves data/ JSON files across git pull.
+# Usage: cd /opt/vps-monitoring && bash scripts/deploy.sh
+set -euo pipefail
+
+APP_DIR="$(cd "$(dirname "$0")/.." && pwd)"
+cd "$APP_DIR"
+
+DATA_BACKUP="/tmp/vps-monitoring-data-backup-$(date +%Y%m%d_%H%M%S)"
+DATA_FILES=(servers.json synology.json homeassistant.json pc_agents.json keenetic.json settings.json metrics.json notifications.json)
+
+echo "📦 Backing up data/ → $DATA_BACKUP"
+mkdir -p "$DATA_BACKUP"
+for f in "${DATA_FILES[@]}"; do
+    [ -f "data/$f" ] && cp "data/$f" "$DATA_BACKUP/$f"
+done
+
+echo "📥 git pull"
+# Never use 'git stash -u' — it removes untracked data/*.json from disk.
+git pull --ff-only origin main
+
+echo "🔄 Restore data if missing"
+for f in "${DATA_FILES[@]}"; do
+    if [ ! -f "data/$f" ] && [ -f "$DATA_BACKUP/$f" ]; then
+        echo "  restore $f"
+        cp "$DATA_BACKUP/$f" "data/$f"
+    fi
+done
+
+echo "🐍 pip install"
+source venv/bin/activate
+pip install -q -r requirements.txt
+
+echo "♻️  restart vps-monitoring"
+systemctl restart vps-monitoring
+sleep 2
+systemctl is-active vps-monitoring
+
+echo "✅ Deploy done. Data backup: $DATA_BACKUP"