feat: 전투 시뮬레이터를 브라우저 Worker로 이관

서버가 권위 환경과 반복 seed를 준비하고 공용 logic 프로세서를 브라우저와 기존 서버 fallback이 함께 사용하도록 변경한다. production Chromium에서 고정 seed와 1000회 Node 결과 동등성을 검증한다.

app/game-api/test/battleSimProcessor.test.ts

@@ -1,4 +1,5 @@
 import { describe, expect, it } from 'vitest';
+import { LiteHashDRBG, RandUtil } from '@sammo-ts/common';
 
 import type { BattleSimJobPayload } from '../src/battleSim/types.js';
 import { processBattleSimJob } from '../src/battleSim/processor.js';
@@ -259,6 +260,26 @@ describe('battle sim processor', () => {
         expect(processBattleSimJob(legacyPayload)).toEqual(processBattleSimJob(baselinePayload));
     });
 
+    it('uses server-issued per-repeat seeds deterministically when no fixed seed is supplied', () => {
+        const firstPayload = buildPayload('battle');
+        delete firstPayload.seed;
+        firstPayload.repeatCnt = 2;
+        firstPayload.seeds = ['server-repeat-0', 'server-repeat-1'];
+        const secondPayload = structuredClone(firstPayload);
+        const observedSeeds: string[] = [];
+
+        const first = processBattleSimJob(firstPayload, {
+            rngFactory: (seed) => {
+                observedSeeds.push(seed);
+                return new RandUtil(LiteHashDRBG.build(seed));
+            },
+        });
+        const second = processBattleSimJob(secondPayload);
+
+        expect(first).toEqual(second);
+        expect(observedSeeds).toEqual(['server-repeat-0', 'server-repeat-1']);
+    });
+
     it('returns the fixed defender ID order for reorder action', () => {
         const payload = buildPayload('reorder');
         const result = processBattleSimJob(payload);

app/game-api/test/battleSimRouter.test.ts

@@ -257,6 +257,58 @@ const buildContext = (options: {
 };
 
 describe('battle router orchestration', () => {
+    it('prepares the authoritative browser-worker payload without queuing server work', async () => {
+        const battleSim = new QueuedBattleSimTransport();
+        const state: WorldStateRow = {
+            id: 1,
+            scenarioCode: 'default',
+            currentYear: 200,
+            currentMonth: 1,
+            tickSeconds: 600,
+            config: { environment: { scenarioEffect: 'event_MoreEffect' } },
+            meta: { scenarioMeta: { startYear: 180 } },
+            updatedAt: new Date('2026-01-01T00:00:00Z'),
+        };
+        const caller = appRouter.createCaller(buildContext({ state, battleSim }));
+        const request = { ...buildBattleRequest(), repeatCnt: 1000 };
+        delete (request as Partial<typeof request>).seed;
+
+        const prepared = await caller.battle.prepareSimulation(request);
+
+        expect(prepared).toMatchObject({
+            action: 'battle',
+            repeatCnt: 1000,
+            scenarioEffect: 'event_MoreEffect',
+            time: { year: 200, month: 1, startYear: 180 },
+            config: { armPerPhase: 500, maxTrainByWar: 110, maxAtmosByWar: 150 },
+        });
+        expect(prepared.unitSet.crewTypes?.length).toBeGreaterThan(0);
+        expect(prepared.seeds).toHaveLength(1000);
+        expect(new Set(prepared.seeds).size).toBe(1000);
+        expect(battleSim.simulateCalls).toBe(0);
+    });
+
+    it('does not allocate repeat seeds when the client supplies a fixed seed', async () => {
+        const battleSim = new QueuedBattleSimTransport();
+        const state: WorldStateRow = {
+            id: 1,
+            scenarioCode: 'default',
+            currentYear: 200,
+            currentMonth: 1,
+            tickSeconds: 600,
+            config: {},
+            meta: {},
+            updatedAt: new Date('2026-01-01T00:00:00Z'),
+        };
+        const caller = appRouter.createCaller(buildContext({ state, battleSim }));
+
+        const prepared = await caller.battle.prepareSimulation(buildBattleRequest());
+
+        expect(prepared.seed).toBe('test-seed');
+        expect(prepared.seeds).toEqual([]);
+        expect(battleSim.simulateCalls).toBe(0);
+    });
+
     it('returns queued then completed results via transport', async () => {
         const battleSim = new QueuedBattleSimTransport();
         const state: WorldStateRow = {
@@ -351,6 +403,9 @@ describe('battle router orchestration', () => {
         } as unknown as DatabaseClient;
 
         const anonymous = appRouter.createCaller(buildContext({ state, battleSim, userId: null, db }));
+        await expect(anonymous.battle.prepareSimulation(buildBattleRequest())).rejects.toMatchObject({
+            code: 'UNAUTHORIZED',
+        });
         await expect(anonymous.battle.simulate(buildBattleRequest())).rejects.toMatchObject({
             code: 'UNAUTHORIZED',
         });
@@ -358,6 +413,10 @@ describe('battle router orchestration', () => {
         const noGeneralUser = appRouter.createCaller(
             buildContext({ state, battleSim, userId: 'user-without-general', db })
         );
+        await expect(noGeneralUser.battle.prepareSimulation(buildBattleRequest())).resolves.toMatchObject({
+            action: 'battle',
+            seed: 'test-seed',
+        });
         await expect(noGeneralUser.battle.simulate(buildBattleRequest())).resolves.toMatchObject({
             status: 'queued',
         });

app/game-api/test/directMutationJournalInventory.test.ts

@@ -96,7 +96,7 @@ const classifications = {
     ],
     operational: ['turnDaemon.pause', 'turnDaemon.resume', 'turnDaemon.run'],
     externalUpload: ['board.uploadImage'],
-    readOnlyMutationTransport: ['battle.simulate'],
+    readOnlyMutationTransport: ['battle.prepareSimulation', 'battle.simulate'],
     sessionOnly: ['auth.exchangeGatewayToken'],
 } as const;
 
@@ -142,7 +142,7 @@ describe('game-api direct mutation journal inventory', () => {
         const classified = Object.values(classifications).flat().sort();
 
         expect(new Set(classified).size).toBe(classified.length);
-        expect(classified).toHaveLength(86);
+        expect(classified).toHaveLength(87);
         expect(actual).toEqual(classified);
     });
 });

app/game-api/test/generalAccessTracking.test.ts

@@ -122,6 +122,7 @@ describe('general access tracking', () => {
             'npc.setNationPolicy': 0,
             'npc.setNationPriority': 0,
             'npc.setGeneralPriority': 0,
+            'battle.prepareSimulation': 0,
             'battle.simulate': 0,
         });
     });