test(combat): cover CombatService LOST persistence

CombatService only had engine-level coverage of the LOST transition.
Add service-level tests that force a loss (character.baseHp: 1) and
assert the persisted status, completedAt, further-action rejection,
and getCombat refresh behavior for a LOST combat.

apps/api/src/combat/combat.service.spec.ts

@@ -497,6 +497,27 @@ describe('CombatService', () => {
       );
     });
 
+    it('ends the combat as LOST, stops persisting new rounds, and rejects further actions', async () => {
+      const state = createState({
+        characters: [character({ baseHp: 1 })],
+      });
+      const { dataSource, service, combatId } = await startedCombat(state);
+
+      const result = await service.performAction(
+        CHARACTER_ID,
+        combatId,
+        CombatAction.ATTACK,
+      );
+
+      expect(result.status).toBe('LOST');
+      expect(dataSource.state.combats[0].status).toBe(CombatStatus.LOST);
+      expect(dataSource.state.combats[0].completedAt).not.toBeNull();
+      await expectCombatDomainError(
+        service.performAction(CHARACTER_ID, combatId, CombatAction.ATTACK),
+        'COMBAT_ALREADY_FINISHED',
+      );
+    });
+
     it('rejects actions on an unknown combat id', async () => {
       const { service } = createService();
 
@@ -565,5 +586,29 @@ describe('CombatService', () => {
         'COMBAT_NOT_FOUND',
       );
     });
+
+    it('keeps returning LOST after the combat has ended', async () => {
+      const state = createState({
+        characters: [character({ baseHp: 1 })],
+      });
+      const context = createService({ state });
+      const started = await context.service.startCombat(
+        CHARACTER_ID,
+        ENCOUNTER_ID,
+      );
+      await context.service.performAction(
+        CHARACTER_ID,
+        started.id,
+        CombatAction.ATTACK,
+      );
+
+      const reloaded = await context.service.getCombat(
+        CHARACTER_ID,
+        started.id,
+      );
+
+      expect(reloaded.status).toBe('LOST');
+      expect(reloaded.player.currentHp).toBe(0);
+    });
   });
 });