feat(combat): validate potions, persist telegraph state, and expose both on the combat DTO

Also updates the pre-existing exact-equality playerState assertion in
combat-equipment-integration.spec.ts, which broke from the new
potionsRemaining field but wasn't listed in the task brief's file scope.

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

@@ -325,6 +325,8 @@ describe('CombatService', () => {
         name: 'Aric Duskwalker',
         maxHp: 100,
         currentHp: 100,
+        potionsRemaining: 2,
+        potionsMax: 2,
       });
       expect(combat.monster).toEqual({
         key: 'ash-rat',
@@ -333,6 +335,7 @@ describe('CombatService', () => {
         maxHp: 45,
         currentHp: 45,
         artworkPath: '/images/monsters/ash-rat.png',
+        pendingIntent: null,
       });
       expect(combat.events).toEqual([]);
       expect(dataSource.state.combats).toHaveLength(1);
@@ -653,6 +656,43 @@ describe('CombatService', () => {
         expect.arrayContaining([{ target: Combat, mode: 'pessimistic_write' }]),
       );
     });
+
+    it('resolves POTION, heals the player, and persists the reduced potion count', async () => {
+      const { service, combatId } = await startedCombat();
+      await service.performAction(CHARACTER_ID, combatId, CombatAction.ATTACK);
+
+      const result = await service.performAction(CHARACTER_ID, combatId, CombatAction.POTION);
+
+      expect(result.player.potionsRemaining).toBe(1);
+      expect(result.player.currentHp).toBe(95);
+
+      const reloaded = await service.getCombat(CHARACTER_ID, combatId);
+      expect(reloaded.player.potionsRemaining).toBe(1);
+    });
+
+    it('rejects POTION once both potions have been used', async () => {
+      const { service, combatId } = await startedCombat();
+
+      await service.performAction(CHARACTER_ID, combatId, CombatAction.POTION);
+      await service.performAction(CHARACTER_ID, combatId, CombatAction.POTION);
+
+      await expectCombatDomainError(
+        service.performAction(CHARACTER_ID, combatId, CombatAction.POTION),
+        'COMBAT_NO_POTIONS_REMAINING',
+      );
+    });
+
+    it('persists the telegraphed Heavy Attack across a reload', async () => {
+      const { service, combatId } = await startedCombat();
+      await service.performAction(CHARACTER_ID, combatId, CombatAction.ATTACK);
+      await service.performAction(CHARACTER_ID, combatId, CombatAction.ATTACK);
+      const telegraphed = await service.performAction(CHARACTER_ID, combatId, CombatAction.ATTACK);
+
+      expect(telegraphed.monster.pendingIntent).toBe('HEAVY_ATTACK');
+
+      const reloaded = await service.getCombat(CHARACTER_ID, combatId);
+      expect(reloaded.monster.pendingIntent).toBe('HEAVY_ATTACK');
+    });
   });
 
   describe('getCombat', () => {