Implement bounded Richese Nexus Betrayal auctions

docs/RULE_DECISIONS.md

@@ -35,6 +35,7 @@ Updated 30 September 2026. This is the authoritative navigation index for existi
 | Nexus lifecycle | Twelve physical cards, phase draw/replacement and alliance forfeiture; native Cunning, absent-faction Secret Ally and Betrayal have separate effects. No blanket Karama immunity. | [Common source contract](NEXUS_CARD_RULES.md), [lifecycle runtime](NEXUS_CARD_RUNTIME.md) |
 | Nexus faction effects | Preserve physical custody, original faction identity and durable effect receipts; use each printed family instead of borrowing another faction's rules by analogy. | [Atreides](NEXUS_ATREIDES_RULES.md), [Harkonnen](NEXUS_HARKONNEN_RULES.md), [BG](NEXUS_BENE_GESSERIT_RULES.md), [Emperor](NEXUS_EMPEROR_RULES.md), [Fremen](NEXUS_FREMEN_RULES.md), [Guild](NEXUS_GUILD_RULES.md) |
 | Expansion Nexus families | Source audit coverage does not imply every panel is playable; consult later runtime records in the status log. | [Ixian Cunning](NEXUS_IXIAN_CUNNING_RULES.md), [Ixian replacement](NEXUS_IXIAN_REPLACEMENT_RULES.md), [Tleilaxu](NEXUS_TLEILAXU_RULES.md), [CHOAM](NEXUS_CHOAM_RULES.md), [Richese](NEXUS_RICHESE_RULES.md), [Ecaz](NEXUS_ECAZ_RULES.md), [Moritani](NEXUS_MORITANI_RULES.md) |
+| Richese Nexus Betrayal auctions | Pause at a valid original prepayment quote. Public self-cache veto discards the exact card without debit/acquisition; another buyer's positive cache/Black Market invoice keeps price/contributions/delivery and earned Harkonnen bonus while overriding the recipient to bank. All publicly possible unallied other-faction held-Nexus seats acknowledge uniformly; private identity controls only own Use. This neutral protocol is an application choice, not publisher timing. Normal hidden-family self-purchases, special-Karama veto and unsupported overlays remain excluded; no native Karama exception certifies them. Bounded engine/SQL/bot/phone scenarios are verified locally; broader verification remains Partial and public starts/full Nexus gates stay closed. | [Printed face, profile, API and saved continuation](NEXUS_RICHESE_RULES.md#bounded-betrayal-auction-contract--30-september-2026), [common privacy protocol](NEXUS_CARD_RULES.md#richese-betrayal-prepayment-protocol), [auction source boundaries](RICHESE_AUCTION_RULES.md) |
 | CHOAM Secret Ally | Absent-faction Collection trade spends one actual Worthless card and the Nexus for two bank spice. It is separate from native Cunning and Auditor; the battle inspection alternative remains missing. | [Prototype contract](NEXUS_CHOAM_SECRET_ALLY.md) |
 | Sapho movement | At a clean boundary, first reorders only remaining unstarted turns; completed turns stay completed. Advanced Guild must have finished or be absent. Last retains existing protection after Guild. | [Existing source contract](JUICE_OF_SAPHO_SOURCE_UPDATE.md#movement-firstlast), [runtime](JUICE_OF_SAPHO_RUNTIME.md) |
 | Basic CHOAM / Leader Skills | Compose existing ordinary skills with native sales and own-leader Ghola revival. Finish the private optional replacement before the exact suspended sale resumes. The free revival remains completed if the resumed sale is canceled. Basic uses five ordinary leaders and 35 Treachery Cards; Auditor remains Advanced and ineligible for skills. | [Integration and source contracts](CHOAM_LEADER_SKILLS.md) |