Integrate exact Ixian Nexus purchased-card replacement

docs/NEXUS_CARD_RULES.md

@@ -63,6 +63,8 @@ The private holder offer contains CHOAM's name; it includes the hand count only
 
 Later focused source contracts cover [Emperor strength, purchases and revival](NEXUS_EMPEROR_RULES.md), [Ixian purchased-card replacement](NEXUS_IXIAN_REPLACEMENT_RULES.md), [Fremen worm and revival effects](NEXUS_FREMEN_RULES.md), and [Richese's separate shipment and auction panels](NEXUS_RICHESE_RULES.md). These audits distinguish implemented work from remaining source/timing questions; current runtime evidence is tracked in [implementation status](IMPLEMENTATION_STATUS.md). Bounded Richese auction and Guild shipment Betrayal checkpoints have their own direct local verification below; neither inherits certification of its complete faction, Nexus family or live deployment from earlier evidence.
 
+The [bounded Ixian Secret Ally replacement integration](NEXUS_IXIAN_REPLACEMENT_RULES.md#bounded-local-runtime-contract) now connects genuine normal paid and printed Karama-paid purchases in a fresh classic/base-deck/Nexus-only local profile. It replaces exactly the purchased physical card, keeps the original settlement once and permits full-hand and genuinely depleted-deck same-card redraw. Harkonnen buyers, cache/Black Market/special origins and combined modules remain guarded. Neutral buyer acknowledgement is an inferred development privacy convention, not publisher policy. Bounded native, private, authenticated recovery, CLI and phone verification is Partial; full-module and deployed acceptance remain open. The adopted unofficial Advanced core PDF contains no Nexus face and settles none of these pending Nexus boundaries.
+
 **Atreides is the first complete effect family to implement.** It has independent rulebook and physical-face evidence, and the engine already has private plan-element inspection. The Nexus effect needs its own cause and receipt rather than temporarily changing the inspecting faction. The second element must differ from the already inspected element. Preserve the original disclosed value if an allowed later battle edit occurs; follow the existing plan commitment rules instead of refreshing an old observation. The card specifies an element, not the entire hand or battle plan. A weapon/defense request uses actual played-card classification, including the published Reinforcements/Harass exclusions, rather than leaking a card merely because it occupies that slot.
 
 **Cancellation needs the original attempted effect.** Betrayal is not a blanket Karama flag. For Atreides, identify the inspection attempt being prevented; for Voice, the command; for a traitor/Face Dancer, the actual revealed identity; for economy, the original invoice and settlement. Do not refund or replay a completed payment merely because the next input happens to be a Nexus play. Effects with no printed phase still need a safe explicit action boundary and cannot bypass another player's committed private choice.