How about using your browser bookmark system - at least until the discourse people stop worrying about where the topic title goes in each line item and address useful suggestions like this?
As an example from OS X Safari, which is the browser I use:
Discourse leaves an unimaginably large amount of cruft in the history file - actually I don’t need to imagine it at all. Each entry I read leaves it’s header and link in the history. I normally just go to the history file when I leave discourse and shift-select the start and finish and bulk delete them all. If there’s an item I think I might want to reference in the near future I just leave it until I decide I don’t need it any longer.
If I think I might want to keep it for awhile I just open the bookmark list and copy-drag it from the history to an appropriate bookmark category.
The history list is sub-headed by day and date. When I’m looking for something it’s easy to just expand/contract each day until I find what I’m looking for.
When an item is saved in the bookmark file the full organizational power of that system is available to move entries from one category to another, reorganize the category tree structure, etc.
I’m not an authority on other browsers, but I suspect they all have similar capabilities.