feat(api): mirror HP onto the character each round and resume regen at combat end

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

@@ -579,6 +579,41 @@ describe('CombatService', () => {
       });
     });
 
+    it('mirrors the player HP onto the character each round while the fight continues', async () => {
+      const { dataSource, service, combatId } = await startedCombat();
+
+      await service.performAction(CHARACTER_ID, combatId, CombatAction.ATTACK);
+
+      expect(dataSource.state.characters[0].currentHp).toBe(95);
+      expect(dataSource.state.characters[0].hpRegenSince).toBeNull();
+    });
+
+    it('restarts regeneration on the character once the fight is won', async () => {
+      const state = createState({ monsters: [monster({ maxHp: 10 })] });
+      const { dataSource, service, combatId } = await startedCombat(state);
+
+      await service.performAction(CHARACTER_ID, combatId, CombatAction.ATTACK);
+
+      expect(dataSource.state.characters[0].currentHp).toBe(
+        dataSource.state.combats[0].playerCurrentHp,
+      );
+      expect(dataSource.state.characters[0].hpRegenSince).toEqual(
+        new Date('2026-08-18T09:00:00.000Z'),
+      );
+    });
+
+    it('restarts regeneration from 0 HP once the fight is lost', async () => {
+      const state = createState({ characters: [character({ baseHp: 1, currentHp: 1 })] });
+      const { dataSource, service, combatId } = await startedCombat(state);
+
+      await service.performAction(CHARACTER_ID, combatId, CombatAction.ATTACK);
+
+      expect(dataSource.state.characters[0].currentHp).toBe(0);
+      expect(dataSource.state.characters[0].hpRegenSince).toEqual(
+        new Date('2026-08-18T09:00:00.000Z'),
+      );
+    });
+
     it('ends the combat as WON, stops persisting new rounds, and rejects further actions', async () => {
       const state = createState({ monsters: [monster({ maxHp: 10 })] });
       const { dataSource, service, combatId } = await startedCombat(state);
@@ -650,11 +685,19 @@ describe('CombatService', () => {
       );
     });
 
-    it('lets a lost encounter be fought again as a fresh combat', async () => {
+    it('lets a lost encounter be fought again once the character has recovered HP', async () => {
       const state = createState({ characters: [character({ baseHp: 1, currentHp: 1 })] });
       const { dataSource, service, combatId } = await startedCombat(state);
       await service.performAction(CHARACTER_ID, combatId, CombatAction.ATTACK);
 
+      // The loss now mirrors 0 HP onto the character (this task); simulate
+      // that regeneration has since restored it before retrying. This test
+      // is about the encounter itself being retryable once the character
+      // can fight again, not about regen math (covered by
+      // CharacterVitalsService's own tests).
+      dataSource.state.characters[0].currentHp = 1;
+      dataSource.state.characters[0].hpRegenSince = null;
+
       const retry = await service.startCombat(CHARACTER_ID, ENCOUNTER_ID);
 
       expect(retry.id).not.toBe(combatId);