Board ownership, freshness, and applied-edit alerts

Every board has an owner, usually the person who created it. The owner can transfer ownership with a request such as "@arialine make @person the owner". Ownership helps the right teammate review changes.

When someone other than the owner applies an edit, Arialine DMs the current owner with the actor, new version and summary. This includes directly applied edits and applied proposals, not just edits in proposal mode. It does not alert the person who applied their own edit. Each alert has Mute this board and Mute all apply alerts. Choosing either updates the alert to a confirmation with Undo mute, which restores only the choice made. A board-level mute follows the owner's identity; it does not silence alerts for a future owner.

The freshness dot is green when there are no pending proposals, yellow when proposals await review, and red when the owner explicitly marks the board stale. The old age-based review reminder DM has been retired; simply reaching two weeks no longer sends a DM or changes the dot. Board versions and source evidence remain in History.