Record that the holder opened Voice Down or picked Escalate - dispatch

Claim-lock R2, the escalation record. The operator HOLDING this alarm tells the other consoles they are about to escalate, so they show "Escalation in progress". Body {action: voice_down|dispatch, generation, action_token}: generation is claim.generation (the ownership generation, which changes when the holder changes and never on a renewal), action_token a client nonce minted once per panel open. There is no expiry: the intent lasts while the alarm is this operator's and is cleared by .../acting/cancel, a close, a claim lapse or a take-over. Under the event row lock: a closed, expired or unqueued alarm is a plain 409; no live claim is 409 claim_changed (claim null); another operator's live claim is 409 claim_held; a stale generation is 409 claim_changed with the current claim; the same token and generation again is a 200 replay that writes nothing, and so is the token of an action that already finished (cancelled, completed, closed, lapsed or taken over) or was replaced by a newer pick (the row remembers the newest 32 per generation): recorded: false, replay: true, it is never revived and never overwrites the newer pick; a new pick needs a new token. Requires claim participation, central staff, and the action's own permission (escalate_voice_down / escalate_dispatch). 404 while CLAIM_ESCALATION_ENABLED is off (or site claims are on, or claim cleanup is off): read claim_escalation_enabled on GET /auth/me first.