card image source not always accessible

[DaveSkender]

When accessing the catalog, images often don't show when behind a VPN or other enterprise firewall. The error shows up as:

Request URL: https://{third-party photo inventory list URL}
Request Method: GET
Status Code: 504 Gateway Timeout (from service worker)
Referrer Policy: strict-origin-when-cross-origin

However, it's more likely that it's blocked.

Consider a nicer "images cannot be retrieved" user error or use a more direct / reliable image source for this demo. Possibly, host a set of usable stock images directly, without relying on third-party APIs.

Done when:

• [ ] not using third party API for image source
• [ ] pattern guidance updated to reflect limitations (e.g., See All and possibly Show More not appropriate for massive data.

[DaveSkender]

Using proxy forwarding isn’t a better option