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>

docker-compose.prod.yml

@@ -31,11 +31,17 @@ services:
           litestream restore -config /etc/litestream.yml /app/data/app.db \
             || echo "==> No backup found, starting fresh"
         fi
+        if [ ! -f /data/landing/.state.sqlite ]; then
+          echo "==> No state DB found, restoring from R2..."
+          litestream restore -config /etc/litestream.yml /data/landing/.state.sqlite \
+            || echo "==> No state backup found, starting fresh"
+        fi
         exec litestream replicate -config /etc/litestream.yml
     env_file: ./.env
     volumes:
       - app-data:/app/data
       - ./litestream.yml:/etc/litestream.yml:ro
+      - /data/padelnomics/landing:/data/landing
     healthcheck:
       test: ["CMD-SHELL", "kill -0 1"]
       interval: 5s