Support multiparty public deals

docs/PUBLIC_DEALS.md

@@ -10,27 +10,38 @@ terms that contradict the rules. The user-supplied revised rulebook, physical
 p. 16 (printed p. 14), records the same principles. This implementation does
 not interpret written terms or decide whether they are legal or impossible.
 
-Two human seats that are not allied with each other can record public written
-terms during play, including while a game decision is open. The recipient may
-accept or decline and the proposer may withdraw an unanswered offer. Both
-participants can vote to release an accepted deal; either may withdraw a
-pending release request. Once both agree, the record is released. Existing
-agreements can be released if participants subsequently become allies. Records
-remain visible and active until both release them, even after the players
-consider the terms fulfilled. Their text is public to the whole table.
+Two to six human seats can record public written terms during play, including
+while a game decision is open. Every pair must be nonallied when the offer is
+made and when each acceptance is recorded. This pairwise interpretation of a
+multi-party offer is provisional; the printed rules do not settle its exact
+online form. The proposer is implicitly in agreement. All recipients must
+accept for the record to become active; any may decline while it remains open,
+and the proposer may withdraw it. Each participant can request or withdraw a
+release; all must agree before release. Existing agreements can still be
+released if participants subsequently become allies. Records remain active
+until unanimously released, even after the players consider terms fulfilled.
+Their text is public to the whole table.
 
 The record itself moves no spice and creates no automatically enforced game
 action. Players remain responsible for honoring valid terms, and an impossible
 part is void under the rules. Existing [bribe controls](BRIBE_CONTROLS.md)
 make actual eligible payments into the recipient's deferred Mentat supply.
-Automatic interpretation, enforcement and impossibility handling, more than
-two parties, AI negotiation and complete multiplayer/deployed acceptance remain
+Automatic interpretation, enforcement and impossibility handling,
+AI negotiation and complete multiplayer/deployed acceptance remain
 open. The text interface is an online convention, not a publisher ruling.
 
-The action uses the normal seat authentication and room version fence. Game
+The action uses the normal seat authentication and room version fence. Older
+two-party records retain their original serialized form and actions. Game
 state carries an additive public ledger; it does not replace the native phase,
 decision, private information or physical components.
 
+The multiparty follow-up passes 28 cases in four related unit files and two
+isolated authenticated HTTP cases, including three signatories across separately
+authenticated faction seats. This does not certify all game combinations.
+An isolated browser room exercised three-party acceptance and unanimous release
+across four human faction seats. The subsequent allied-acceptance control was
+verified by a focused component test rather than that browser run.
+
 Seven related unit files pass 43 cases, including a native Truthtrance response
 continuation; an isolated authenticated HTTP case covers three public views,
 seat-authorized consent, release and subsequent play. The UI tests cover