feat: landing zone backup to R2 via rclone + Litestream

Landing files (append-only JSON.gz) synced to R2 every 30 min via
systemd timer + rclone. Extraction state DB (.state.sqlite) continuously
replicated via Litestream (second DB entry). Auto-restore on container
startup for both app.db and .state.sqlite. Reuses existing R2 bucket
and credentials — no new env vars needed.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

infra/restore_landing.sh

@@ -0,0 +1,27 @@
+#!/bin/sh
+# Restore landing zone files from R2.
+# The extraction state DB (.state.sqlite) is restored automatically by
+# the Litestream container on startup — this script handles the data files only.
+#
+# Requires: rclone, LITESTREAM_R2_* env vars (from /opt/padelnomics/.env)
+#
+# Usage:
+#   source /opt/padelnomics/.env && bash infra/restore_landing.sh
+
+set -eu
+
+LANDING_DIR="${LANDING_DIR:-/data/padelnomics/landing}"
+BUCKET_PREFIX="${LITESTREAM_R2_BUCKET:?LITESTREAM_R2_BUCKET not set}/padelnomics/landing"
+
+echo "==> Restoring landing zone from R2 to ${LANDING_DIR}..."
+
+rclone sync ":s3:${BUCKET_PREFIX}" "$LANDING_DIR" \
+    --s3-provider Cloudflare \
+    --s3-access-key-id "${LITESTREAM_R2_ACCESS_KEY_ID:?not set}" \
+    --s3-secret-access-key "${LITESTREAM_R2_SECRET_ACCESS_KEY:?not set}" \
+    --s3-endpoint "https://${LITESTREAM_R2_ENDPOINT:?not set}" \
+    --s3-no-check-bucket \
+    --exclude ".state.sqlite*" \
+    --progress
+
+echo "==> Landing zone restored to ${LANDING_DIR}"