Route Advanced Emperor allied auction funding

docs/NEXUS_EMPEROR_RULES.md

@@ -353,7 +353,25 @@ compulsory funding below. Seller-paid Secret Ally purchase remains unfinished.
 
 ## Betrayal and remaining decisions
 
-Normal Emperor-funded auction help goes to the ally and is paid back to Emperor, according to November's FAQ. Therefore forcing its contribution cannot automatically be implemented as transferring its spice to the bank. Bind the actual allied purchase and its original price/contributions. [November FAQ, p.2](https://www.gf9games.com/dune/wp-content/uploads/2020/11/Dune-FAQ-Nov-2020.pdf#page=2)
+The earlier Basic interpretation sends normal Emperor-funded auction help to
+the ally and back to Emperor, following [November FAQ, p.2](https://www.gf9games.com/dune/wp-content/uploads/2020/11/Dune-FAQ-Nov-2020.pdf#page=2).
+The Advanced source cutover below changes the recipient of a contribution;
+bind the actual allied purchase and its original price and payer shares.
+
+### Advanced Emperor contribution recipient — 29 October 2026
+
+The user-authorized supplied revised rulebook, physical p. 15 (printed p. 13),
+Bidding, directs Emperor's contribution to an ally's Treachery Card purchase
+to the Spice Bank. An amount transferred directly using Emperor's alliance
+ability is instead the buyer's own spice and follows the purchase's normal
+recipient. This is an Advanced source cutover; Basic retains the earlier
+interpretation above. Ordinary and Richese paid-lot prototypes preserve the
+actual payer and recipient legs through settlement. For example, if an ally
+buys an ordinary card for six with two contributed by Emperor, four goes to
+Emperor and two to the bank. Income cancellation can affect only the eligible
+Emperor income, not return or replay the bank contribution. This implementation
+is partial and does not certify Nexus purchase variants, all optional-module
+interactions or full Advanced play.
 
 ### Implemented battle alternative (bounded)