"Remove from this list": take one memory off the Memories ledger.

WHAT THIS IS NOT. It is not an undo and it is not a delete. The version row stays, the document keeps answering exactly as it did a second ago, and the history behind the editor still shows every wording the desk has ever had. Versions are append-only — that is what makes Undo trustworthy — so the only honest "delete" over them is one that removes the ROW FROM THE LIST, which is what the owner is actually asking for when a superseded or never-applied memory sits there with no control on it.

Removing a LIVE memory therefore leaves it live. The surface says so: for a live row the destructive action is Undo ("puts the earlier wording back") and this one is the quiet cleanup beside it.

IDEMPOTENT (mark_version_ledger_hidden keeps the first stamp): a second press — or a second tab — is a 200 that changed nothing, because a row the owner cannot see any more must never answer with an error they cannot act on.

Refusals: 400 a malformed id · 404 not this AgentDesk's memory · 409 the version carries no memory to remove.