Implement Grumman collection and private stacked Terror choices

Add conserved token collection with four bank spice, owner-only stack selection, recovery proofs, controls and AI. Preserve unresolved removal and expansion release gates. Verified 3712 offline cases, types, lint, production build, 40 HTTP cases, three-seat desktop/mobile play, and unchanged 3081 preexisting saved games.

game/grumman-collection-options.ts

@@ -0,0 +1,57 @@
+import type { Action, GameView } from './engine';
+
+/** Use the current private projection; do not reconstruct hidden Terror supply. */
+export function grummanCollectionCanAct(g: GameView): boolean {
+  return !!(
+    g.status === 'playing' &&
+    g.grummanCollection?.player === g.me &&
+    g.decision?.kind === 'grummanCollection' &&
+    g.decision.player === g.me &&
+    g.decision.event === g.grummanCollection.event &&
+    !g.response &&
+    !g.truthtrance &&
+    !g.phaseOpening &&
+    !g.automaticContinuationPending
+  );
+}
+
+export function grummanCollectionChoice(
+  g: GameView,
+  token: string,
+  territory: string,
+): { blocked: string | null; action: Action | null } {
+  const offer = g.grummanCollection;
+  let blocked: string | null = null;
+  if (!grummanCollectionCanAct(g))
+    blocked = 'Wait for the current choice to finish.';
+  else if (offer!.blocked) blocked = offer!.blocked;
+  else if (!offer!.tokens.some((candidate) => candidate.id === token))
+    blocked = 'Choose a currently available Terror token.';
+  else if (!offer!.destinations.some((candidate) => candidate.id === territory))
+    blocked = 'Choose a current destination stronghold.';
+  return {
+    blocked,
+    action: blocked
+      ? null
+      : {
+          type: 'decision',
+          event: offer!.event,
+          mode: 'add',
+          token,
+          territory,
+        },
+  };
+}
+
+export function grummanCollectionActions(g: GameView): Action[] {
+  if (!grummanCollectionCanAct(g)) return [];
+  const offer = g.grummanCollection!;
+  const choice = grummanCollectionChoice(
+    g,
+    offer.tokens[0]?.id ?? '',
+    offer.destinations[0]?.id ?? '',
+  );
+  return [
+    choice.action ?? { type: 'decision', event: offer.event, decline: true },
+  ];
+}