Summary\n- stamp newly placed orders with the active signed-in user's email\n- render, update, and reorder only orders owned by the current session\n- require the same ownership check before invoice PDF/print lookup returns an order\n- remove stale duplicate/broken order-handler code that prevented js/main.js from parsing\n\n## Why\nThe app is frontend-only and stores orders in localStorage, so the practical fix for #455 is to enforce ownership at the local order access layer rather than adding nonexistent Express order endpoints.\n\nFixes #455\n\n## Testing\n- node --check js/auth.js\n- node --check js/invoice.js\n- node --check js/main.js\n- git diff --check