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>

litestream.yml

@@ -6,9 +6,12 @@
 #   LITESTREAM_R2_SECRET_ACCESS_KEY
 #   LITESTREAM_R2_ENDPOINT      e.g. <account-id>.r2.cloudflarestorage.com
 #
-# Recovery:
+# Recovery (app database):
 #   litestream restore -config /etc/litestream.yml /app/data/app.db
 #   litestream restore -config /etc/litestream.yml -timestamp "2026-01-15T12:00:00Z" /app/data/app.db
+#
+# Recovery (extraction state):
+#   litestream restore -config /etc/litestream.yml /data/landing/.state.sqlite
 
 dbs:
   - path: /app/data/app.db
@@ -19,3 +22,12 @@ dbs:
         endpoint: https://${LITESTREAM_R2_ENDPOINT}
         retention: 8760h
         snapshot-interval: 6h
+
+  - path: /data/landing/.state.sqlite
+    replicas:
+      - url: s3://${LITESTREAM_R2_BUCKET}/padelnomics/state.sqlite
+        access-key-id: ${LITESTREAM_R2_ACCESS_KEY_ID}
+        secret-access-key: ${LITESTREAM_R2_SECRET_ACCESS_KEY}
+        endpoint: https://${LITESTREAM_R2_ENDPOINT}
+        retention: 8760h
+        snapshot-interval: 24h