CLI Download Clear

`ed download clear`

Forgets what has finished.

Usage:

ed download clear [--everything] [--json]

Options:

Name	Type / values	Default	What it does
`--everything`	flag	off	Clears what is still queued or running as well.
`--json`	flag	off	Emits one JSON document on stdout.

There are no positional arguments and no --yes guard. Without --everything it drops the done, failed and interrupted records and leaves queued, resolving and downloading alone, which is the safe sweep after a batch has run. With --everything the file is emptied whatever state things are in. Neither form deletes a downloaded file; only the list is cleared.

--json shape:

{
  "remaining": 2,
  "removed": 9
}

Examples:

ed download clear
ed download clear --everything
ed download clear --json

$ ed download clear
cleared 9

Behaviour: clearing an already empty queue reports cleared 0 and exits 0 rather than failing. downloadQueueChanged is posted afterwards, so a running Edith empties its Download sheet to match. Note that --everything forgets an in-flight download without stopping it, exactly as rm does.