Check out Zotero: https://www.zotero.org/
Zotero is an open source bibliography manager. It's my main go to tool for generating works cited pages, like during essays.
But, it also has a browser extension, which can download, and archive sites or academic articles you are adding to the sources. I would then use the fulltext search that zotero provides for easy searching of sources.
Unfortunately, it's not hosted, which would make it difficult to share.
EDIT: It does look like the server component is open source, AGPLv3: https://github.com/zotero/dataserver/
But, I cannot find any deployment instructions. But, it looks like their hosted version lets users create groups of shared items, including sharing archived snapshots of the various items.