IndexedDB corrupted by external opener skipping onupgradeneeded stores

IndexedDB database opened at version N by external code (e.g. headless browser test) without an onupgradeneeded handler creates the DB at that version with zero object stores. When the application later opens the same DB at the same version, onupgradeneeded does NOT fire (version matches), so stores are never created. All subsequent transactions fail silently or throw "object store not found" errors. The app appears to work (messages load via WebSocket) but client-side persistence is completely broken.