tdhky …plugin for the site that will automatically create archive links
Sorry but this is very unlikely to be implemented as a plugin for the website. It’s difficult to automatically know what to collect from different website’s without including many irrelevant elements.
Squirrel free arx services only take snapshots of pages - so text, links, html, embedded images but not the thing that the links point to.
For the reasons Squirrel mentioned, I think it’s better to simply save images of tweets/static content and then upload it in the [Login to see the link] to insert into your post. You could use a free online service ([Login to see the link]) to convert a webpage to an image or take snapshots youself using [Login to see the link], [Login to see the link].
For videos and other content, there are many tools to download video and save it to your computer ([Login to see the link] & [Login to see the link]). If you are a VIP member you can upload videos directly to your account but other members will need to upload to a cloud service or one of the many tube sites available.
When moderating discussions we are now placing any links that no longer work under the “Dead links” section of the OP to cleanup the content but keep them available should they come back to life.