Ops: add Proxmox migration tooling and runbook

Add end-to-end migration scripts for inventory, precopy, cutover, smoke tests, rollback, and post-migration checks. Include an operational runbook and Proxmox env template to move Hördle behind Nginx Proxy Manager while preserving persistent volumes safely.

scripts/backup-persistence.sh

@@ -0,0 +1,39 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Erstellt ein lokales Backup der Persistenzdaten.
+# Ziel: data/prod.db + public/uploads
+
+APP_DIR="${APP_DIR:-$(pwd)}"
+BACKUP_DIR="${BACKUP_DIR:-$APP_DIR/backups/persistence}"
+TIMESTAMP="$(date +%Y%m%d_%H%M%S)"
+OUT_DIR="$BACKUP_DIR/$TIMESTAMP"
+
+cd "$APP_DIR"
+
+mkdir -p "$OUT_DIR"
+
+echo "== Hördle Persistenz-Backup =="
+echo "Quelle: $APP_DIR"
+echo "Ziel:   $OUT_DIR"
+
+if [ -f "data/prod.db" ]; then
+  if command -v sqlite3 >/dev/null 2>&1; then
+    sqlite3 "data/prod.db" ".timeout 5000" ".backup '$OUT_DIR/prod.db'"
+  else
+    cp "data/prod.db" "$OUT_DIR/prod.db"
+  fi
+  sha256sum "$OUT_DIR/prod.db" > "$OUT_DIR/prod.db.sha256"
+else
+  echo "Warnung: data/prod.db fehlt."
+fi
+
+if [ -d "public/uploads" ]; then
+  tar -C "public" -czf "$OUT_DIR/uploads.tar.gz" "uploads"
+  sha256sum "$OUT_DIR/uploads.tar.gz" > "$OUT_DIR/uploads.tar.gz.sha256"
+else
+  echo "Warnung: public/uploads fehlt."
+fi
+
+echo "$TIMESTAMP" > "$BACKUP_DIR/latest"
+echo "Backup abgeschlossen: $OUT_DIR"