There is no way to delete unwanted documents, groups, or comments from your computer.
We have an old "delete document" button that does not work properly because the document is usually synced back to your computer again.
Solution
Create a new workflow for removing Comments, Documents, and Groups. All options menus for these entities will have a "Remove" button that will delete the doc/group/comment locally, and will add it to a database to ban future sync of that resource.
We should remove the index+backlinks of this resource entirely, but we shouldn't remove other entities because that may not be the user's intention. Except when deleting a document, we will delete all comments that target that doc. We will also ban future comments on that document.
When clicking a link to a removed entity, or when embedding a removed entity, we will have a special "not found because you removed this" error page, which will offer a "bring it back" button. When you click this:
The "removal" row will be deleted from the database, allowing sync of this entity again
We will trigger discovery (DHT or otherwise) of this entity to try and load it for you.
To review the content that you have removed, we will have a new page that shows all removed content. To avoid cluttering the UI, this page can be accessed through the menu but not the sidebar. For each entity you have removed, this page will show:
The entity ID
The time you removed it
The button to "bring it back"
Scope
1-2 weeks of backend+frontend
Rabbit Holes
No known rabbit holes
No Goes
Account removal/banning will be handled in a follow-up project
When you remove a group, the documents under the group are not removed (until a future project).