fix(game-api): 시나리오 아이템 표시 순서 통일

JSONB에 저장된 품목과 수량을 유지하며 원본 시나리오 순서로 구매·명장일람·유산·전투 시뮬레이터 선택지를 구성한다.

app/game-api/src/services/scenarioItemOrder.ts

@@ -0,0 +1,44 @@
+import { asRecord, isRecord } from '@sammo-ts/common';
+import { loadScenarioDefinitionById } from '@sammo-ts/game-engine/scenario/scenarioLoader.js';
+import {
+    loadLegacyDefaultUniqueItemPool,
+    resolveLegacyPurchasableItemKeys,
+} from '@sammo-ts/logic/rewards/legacyUniqueItemPool.js';
+
+/** JSONB does not retain the item key order declared by the scenario resource. */
+export const loadScenarioItemOrder = async (scenarioCode: string): Promise<readonly string[] | undefined> => {
+    const normalized = scenarioCode.replace(/^scenario_/i, '').replace(/\.json$/i, '');
+    if (!/^\d+$/.test(normalized) || !Number.isSafeInteger(Number(normalized))) {
+        return undefined;
+    }
+    try {
+        const scenario = await loadScenarioDefinitionById(Number(normalized));
+        const configConst = scenario.config.const;
+        const keys = Object.values(asRecord(configConst.allItems)).flatMap((entries) => Object.keys(asRecord(entries)));
+        if (keys.length > 0) return keys;
+
+        const defaultUniques = await loadLegacyDefaultUniqueItemPool();
+        return [
+            ...resolveLegacyPurchasableItemKeys(configConst),
+            ...Object.values(defaultUniques).flatMap((entries) => Object.keys(entries ?? {})),
+        ];
+    } catch (error) {
+        // Old saved seasons can outlive their scenario resource. Keep the stored entries available.
+        if (isRecord(error) && error.code === 'ENOENT') return undefined;
+        throw error;
+    }
+};
+
+export const orderScenarioItemEntries = <T>(
+    entries: Record<string, T>,
+    itemOrder: readonly string[] | undefined
+): [string, T][] => {
+    const ordered: [string, T][] = [];
+    const remaining = new Map(Object.entries(entries));
+    for (const key of itemOrder ?? []) {
+        if (!remaining.has(key)) continue;
+        ordered.push([key, remaining.get(key)!]);
+        remaining.delete(key);
+    }
+    return [...ordered, ...remaining];
+};