Implement Homeworld mechanics through Caladan reinforcement checkpoint

Connect typed Homeworld custody, transport, battle, income, revival and Caladan reinforcement flows with private multiplayer recovery and controls. Preserve the optimized test workflow and keep unfinished rules modes gated. Verified with 3682 offline tests, typecheck, lint, production build and 40 HTTP tests; existing saved games remain unchanged.

game/caladan-reinforcement-options.ts

@@ -0,0 +1,70 @@
+import type { Action, GameView } from './engine';
+
+/** The resolved battle's projected opportunity is the sole client authority. */
+export function caladanReinforcementCanAct(g: GameView): boolean {
+  return !!(
+    g.status === 'playing' &&
+    g.caladanReinforcement?.player === g.me &&
+    g.decision?.kind === 'caladanReinforcement' &&
+    g.decision.player === g.me &&
+    g.decision.event === g.caladanReinforcement.event &&
+    !g.response &&
+    !g.truthtrance &&
+    !g.phaseOpening &&
+    !g.automaticContinuationPending
+  );
+}
+
+export function caladanReinforcementChoice(
+  g: GameView,
+  destination: string,
+): { blocked: string | null; action: Action | null } {
+  const offer = g.caladanReinforcement;
+  const target = offer?.destinations.find(
+    (option) => option.id === destination,
+  );
+  let blocked: string | null = null;
+  if (!caladanReinforcementCanAct(g))
+    blocked = 'Wait for the current choice to finish.';
+  else if (offer!.blocked) blocked = offer!.blocked;
+  else if (offer!.amount !== 1)
+    blocked = 'This battle reinforcement is no longer available.';
+  else if (!target) blocked = 'Choose a current reinforcement destination.';
+  else if (target.blocked) blocked = target.blocked;
+  return {
+    blocked,
+    action: blocked
+      ? null
+      : { type: 'decision', event: offer!.event, destination, amount: 1 },
+  };
+}
+
+/** Reinforce an already occupied sector when possible. No opposing private
+ * information or reconstructed battle result is needed for this fallback. */
+export function caladanReinforcementActions(g: GameView): Action[] {
+  if (!caladanReinforcementCanAct(g)) return [];
+  const offer = g.caladanReinforcement!;
+  const own = g.players.find((player) => player.id === g.me);
+  const choices = offer.destinations
+    .map((target) => ({
+      target,
+      action: caladanReinforcementChoice(g, target.id).action,
+    }))
+    .filter((choice) => choice.action);
+  const occupied = choices.find(
+    ({ target }) =>
+      (own?.forces[
+        target.sector === undefined
+          ? target.id
+          : `${offer.territory}:${target.sector}`
+      ] ?? 0) > 0,
+  );
+  return [
+    occupied?.action ??
+      choices[0]?.action ?? {
+        type: 'decision',
+        event: offer.event,
+        decline: true,
+      },
+  ];
+}