Deletion
Deleting a source deletes the file and everything made from it
One action removes four things: the file is unlinked from disk, its chunks are deleted, the facts extracted from it are deleted, and the source row itself is deleted. There is no archive copy, no trash, and no flag that hides it while keeping it.
What survives, and should, is anything already written into the assumption ledger, because a number you have since confirmed or edited by hand is yours rather than the file's. Rebuild the twin after deleting a source and the ledger is recomputed from what is left, so a deleted file stops influencing the model at that point.
Deleting a twin removes its sources, chunks, facts, assumptions, scenarios, runs and questions together. Closing your account removes your twins. If you self host and want uninstalling the plugin to remove the tables and the files too, there is a setting for that which ships switched off so an accidental deactivation does not destroy anything.