Add scheduled Square catalog refresh via Docker sidecar

Catalog data only refreshed on first boot, admin button click, or
checkout retry — nothing kept it fresh on a schedule despite the
cache-refresh endpoint being built for cron use. A Next instrumentation
hook was tried first but broke the build (middleware.ts forces
instrumentation.ts into the same edge bundle, which can't resolve
fs/path/crypto). Using a lightweight cron sidecar in the compose stack
instead, so it ships with the deployment regardless of host.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

docker-compose.yml

@@ -98,6 +98,27 @@ services:
       timeout: 10s
       retries: 3
 
+  # ── Scheduled Square catalog refresh ─────────────────────────────────────────
+  # Hits estore's cache-refresh endpoint on a timer so catalog/pricing edits made
+  # in Square show up without a redeploy or manual admin-panel refresh. Runs as
+  # part of the stack itself, so it works on any host this compose file is deployed to.
+  estore-cache-refresh:
+    image: alpine:3.20
+    container_name: bpb-estore-cache-refresh
+    env_file: ./estore/.env
+    depends_on:
+      estore:
+        condition: service_healthy
+    entrypoint: >
+      sh -c "
+      apk add --no-cache curl >/dev/null 2>&1;
+      while true; do
+        curl -sf -X POST http://estore:3000/shop/api/cache/refresh -H \"Authorization: Bearer $$CACHE_REFRESH_SECRET\" || echo 'cache refresh failed';
+        sleep 21600;
+      done
+      "
+    restart: unless-stopped
+
   # ── OSRM download (runs once, exits) ─────────────────────────────────────────
   # Downloads the PBF map file into the shared volume if not already present.
   osrm-download: