Bind Truthtrance alliance promises to actual Nexus closure

components/alliance-claim-fields.tsx

@@ -0,0 +1,42 @@
+'use client';
+
+import { parseAllianceClaim, type AllianceClaim } from '@/game/alliance-promises';
+
+type Partner = { id: string; name: string };
+export function allianceClaimInputError(value: unknown, partners?: readonly Partner[]): string | null {
+  try {
+    const claim = parseAllianceClaim(value);
+    return partners && !partners.some(partner => partner.id === claim.partner)
+      ? 'Choose one of the current alliance partners.' : null;
+  } catch (error) { return error instanceof Error ? error.message : 'Choose the current turn and another player.'; }
+}
+
+/** The parent supplies this Nexus turn and its current named-other choices. */
+export function AllianceClaimFields(props: {
+  value: AllianceClaim;
+  onChange: (claim: AllianceClaim) => void;
+  partners: readonly Partner[];
+  disabled?: boolean;
+}) {
+  const error = allianceClaimInputError(props.value, props.partners);
+  return <fieldset className="grid gap-2" disabled={props.disabled} aria-label="Final alliance at this Nexus close">
+    <legend>Final alliance at this Nexus close</legend>
+    <p>Turn {props.value.turn} · Current Nexus</p>
+    <label htmlFor="truth-alliance-partner">Named alliance partner</label>
+    <select id="truth-alliance-partner" disabled={props.disabled}
+      value={props.partners.some(partner => partner.id === props.value.partner) ? props.value.partner : ''}
+      onChange={event => {
+        const next = { ...props.value, partner: event.currentTarget.value };
+        if (!props.disabled && !allianceClaimInputError(next, props.partners)) props.onChange(parseAllianceClaim(next));
+      }}>
+      <option value="">Choose another player</option>
+      {props.partners.map(partner => <option key={partner.id} value={partner.id}>{partner.name}</option>)}
+    </select>
+    {error && <p role="alert">{error}</p>}
+    <p className="fine">
+      This asks about actual membership when this Nexus closes. Offers alone are not alliances.
+      A Yes needs an existing alliance or a real reciprocal invitation; it cannot promise the other player’s consent.
+      Otherwise No or unknown may apply, and the holder can ask again or save the card.
+    </p>
+  </fieldset>;
+}