Integrate exact Ixian Nexus purchased-card replacement

components/game-table.tsx

@@ -81,6 +81,7 @@ import { SemutaReaction } from './semuta-reaction';
 import { ChoamKull } from './choam-kull';
 import { NexusRicheseBetrayal } from './nexus-richese-betrayal';
 import { NexusGuildBetrayal } from './nexus-guild-betrayal';
+import { NexusIxianReplacement } from './nexus-ixian-replacement';
 import { OrnithopterMovement } from './ornithopter-movement';
 import { DiscoveryOrnithopterMovement } from './discovery-flight-movement';
 import { PlanetologistMovement } from './planetologist-movement';
@@ -305,8 +306,8 @@ export function GameTable({
   );
   const reactionBusy =
     transportBusy || !!g.roomControl?.paused || !!g.roomControl?.closed || !!me.autopilot;
-  const busy = reactionBusy || g.automaticContinuationPending || !!g.semutaReaction || !!g.kullReaction || !!g.richeseBetrayalReaction || !!g.guildBetrayalReaction;
-  const reactionOwnsControls = !!g.kullReaction || !!g.kullCounterEvent || !!g.richeseBetrayalReaction || !!g.guildBetrayalReaction;
+  const busy = reactionBusy || g.automaticContinuationPending || !!g.semutaReaction || !!g.kullReaction || !!g.richeseBetrayalReaction || !!g.guildBetrayalReaction || !!g.nexusIxianReplacement;
+  const reactionOwnsControls = !!g.kullReaction || !!g.kullCounterEvent || !!g.richeseBetrayalReaction || !!g.guildBetrayalReaction || !!g.nexusIxianReplacement;
   const canActivateKarama = (card: Card) =>
     !g.karamaBlocked && canUseAsKaramaRole(g, me, card);
   const traitorBattle = g.battle;
@@ -790,6 +791,13 @@ export function GameTable({
           a.event !== guildReaction.event ||
           (a.type === 'guildBetrayalUse' && (!guildReaction.canUse || guildReaction.blocked))) return;
     }
+    const replacement = g.nexusIxianReplacement;
+    if (replacement && a.type !== 'setAutopilot') {
+      if (reactionBusy || g.status !== 'playing' || !replacement.canPass || replacement.buyer !== me.id ||
+          (a.type !== 'nexusIxianReplacementPass' && a.type !== 'nexusIxianReplacementUse') ||
+          a.event !== replacement.event ||
+          (a.type === 'nexusIxianReplacementUse' && (!replacement.canUse || replacement.blocked))) return;
+    }
     void send(a);
   };
   const choose = (id: string) => {
@@ -1077,6 +1085,14 @@ export function GameTable({
           <a href="/rules?topic=nexus-guild-betrayal#nexus-guild-betrayal">Preview rules and limits</a>
         </p>
       )}
+      {g.nexusIxianReplacementPreview && (
+        <p className="notice" role="status">
+          Ixian Nexus purchased-card replacement development preview · classic Basic/Advanced,
+          base Treachery and Nexus only. Normal paid and printed Karama purchases are supported;
+          Harkonnen buyers and special auctions are guarded. Not complete Ixian or certified Nexus rules.{' '}
+          <a href="/rules?topic=nexus-ixian-replacement#nexus-ixian-replacement">Preview rules and limits</a>
+        </p>
+      )}
       {g.status !== 'lobby' && (
         <nav className="phase-track" aria-label="Turn phases">
           {PHASES.map((p, i) => (
@@ -1721,6 +1737,8 @@ export function GameTable({
             <NexusRicheseBetrayal game={g} act={act} busy={reactionBusy} />
           ) : g.kullReaction ? (
             <ChoamKull game={g} act={act} busy={reactionBusy} />
+          ) : g.nexusIxianReplacement ? (
+            <NexusIxianReplacement game={g} act={act} busy={reactionBusy} />
           ) : g.nexusCards?.waiting.length ? (
             <p className="muted">The next phase begins when the remaining Nexus card choices are finished.</p>
           ) : g.truthtrance ? (
@@ -2607,6 +2625,8 @@ export function GameTable({
                   {g.players.find((p) => p.id === g.decision?.player)?.name} to
                   complete this decision.
                 </p>
+              ) : g.decision.kind === 'nexusIxianReplacement' ? (
+                <NexusIxianReplacement game={g} act={act} busy={reactionBusy} />
               ) : g.decision.kind === 'nullentropy' ? (
                 <NullentropySearch game={g} act={act} busy={busy} />
               ) : g.decision.kind === 'richeseAllyOpportunity' ? (
@@ -3484,7 +3504,7 @@ export function GameTable({
                     accept: false,
                   })}
                 </>
-              ) : (
+              ) : g.decision.kind === 'battleCards' && (
                 <>
                   <p className="muted">
                     You may keep or discard each card played in this battle.

components/nexus-ixian-replacement.tsx

@@ -0,0 +1,80 @@
+'use client';
+
+import type { Action, GameView } from '@/game/engine';
+import { nexusCardMode } from '@/game/nexus-cards';
+import { CardInspector, CardRules } from './card-inspector';
+import { NexusCardFace } from './nexus-cards';
+import { Button } from './ui/button';
+
+/** The public boundary is neutral; only the buyer's projection authorizes a choice. */
+export function NexusIxianReplacement({ game, act, busy }: {
+  game: GameView;
+  act: (action: Action) => void;
+  busy: boolean;
+}) {
+  const offer = game.nexusIxianReplacement;
+  if (!offer) return null;
+  const buyer = game.players.find((player) => player.id === offer.buyer);
+  const own = game.players.find((player) => player.id === game.me);
+  const canRespond = !!offer.event && offer.buyer === game.me && offer.canPass;
+  const canUse = canRespond && offer.canUse && !offer.blocked && !!offer.purchased;
+  const priorityBlocked = !!game.truthtrance || !!game.response || !!game.phaseOpening ||
+    !!game.automaticContinuationPending || !!game.kullReaction || !!game.kullCounterEvent ||
+    !!game.richeseBetrayalReaction || !!game.guildBetrayalReaction || !!game.semutaReaction ||
+    !!game.nexusCards?.waiting.length || !!game.nexusTraitors?.pending ||
+    (!!game.decision && (game.decision.kind !== 'nexusIxianReplacement' ||
+      game.decision.player !== offer.buyer || game.decision.event !== offer.event));
+  const disabled = busy || game.status !== 'playing' || game.phase !== 3 || priorityBlocked ||
+    !!game.roomControl?.paused || !!game.roomControl?.closed || !!own?.autopilot;
+  const ownIxianMode = game.nexusCards?.card === 'ixians' && own
+    ? nexusCardMode('ixians', own.faction, game.players.map((player) => player.faction))
+    : undefined;
+
+  return (
+    <section aria-label="Purchased card choice" data-testid="nexus-ixian-replacement" className="notice min-w-0 space-y-3">
+      <h3>Purchased card choice</h3>
+      <p>{buyer?.name ?? 'The buyer'} chooses whether to keep the completed purchase before the auction continues.</p>
+      <p className="fine">
+        This neutral development-preview boundary is offered independently of the buyer’s private Nexus face.
+        Only the buyer can choose. The original payment stays paid; this is not another purchase or auction.{' '}
+        <a href="/rules?topic=nexus-ixian-replacement#nexus-ixian-replacement">Purchased-card timing and preview limits</a>
+      </p>
+      {canRespond && offer.purchased && (
+        <article aria-label="Your purchased Treachery Card" className="treachery-card">
+          <h4>{offer.purchased.name}</h4>
+          <CardRules card={offer.purchased} />
+          <CardInspector card={offer.purchased} />
+        </article>
+      )}
+      {game.nexusCards?.card === 'ixians' && (
+        <div aria-label="Your private Ixian Nexus card">
+          <NexusCardFace card="ixians" mode={ownIxianMode} />
+          {canRespond && <p className="fine">
+            Secret Ally requires you to be unallied with native Ixians absent. In this preview,
+            eligible Use spends your Ixian Nexus and discards only the exact Treachery Card just purchased,
+            then draws the actual next card from the Treachery Deck. It does not take an unsold auction card.
+            If the deck is empty, the discard is reshuffled after your purchased card enters it;
+            drawing that same physical card again is legal. Keeping retains both cards.
+          </p>}
+        </div>
+      )}
+      {!canRespond ? (
+        <p aria-live="polite">Waiting for {buyer?.name ?? 'the buyer'}’s purchased card choice.</p>
+      ) : (
+        <>
+          {offer.blocked && <p className="fine">{offer.blocked}</p>}
+          <Button data-testid="nexus-ixian-replacement-pass" className="game-action min-h-11 whitespace-normal" disabled={disabled}
+            onClick={() => { if (!disabled) act({ type: 'nexusIxianReplacementPass', event: offer.event }); }}>
+            Keep purchased card
+          </Button>
+          {canUse && (
+            <Button data-testid="nexus-ixian-replacement-use" className="game-action min-h-11 whitespace-normal" disabled={disabled}
+              onClick={() => { if (!disabled) act({ type: 'nexusIxianReplacementUse', event: offer.event }); }}>
+              Use Ixian Nexus · replace purchased card
+            </Button>
+          )}
+        </>
+      )}
+    </section>
+  );
+}