Auto-handle URLs to Flickr images

**Is your feature request related to a problem? Please describe.**
If I go to a Flickr page (e.g., https://www.flickr.com/photos/189067843@N06/50042692202/in/photostream/) and get the URL from the "share" button (e.g., https://flic.kr/p/2jf6SVY), pasting that URL in hubs results in a web page link, not an image.

**Describe the solution you'd like**
Hubs should find the image in that page and use it.

**Describe alternatives you've considered**
none

**Additional context**
May actually be a bug/feature-request for a package dependency, unsure.

Start by tracing how Reticulum handles pasted URLs and identifies image pages, then investigate whether the Flickr share URL can be resolved through the current dependency or needs project changes. Done means a flic.kr URL such as the example is recognized as the underlying Flickr image rather than displayed only as a webpage link.

Written by the indexing model from the issue text.