✨Feature: implement post-combat rewards system with XP tracking and creature defeat logging

src/types/state.ts

@@ -215,6 +215,8 @@ export type RunState = {
   dungeon: DungeonState;
   adventurerSnapshot: AdventurerState;
   activeCombat?: CombatState;
+  defeatedCreatureIds: string[];
+  xpGained: number;
   log: LogEntry[];
   pendingEffects: RuleEffect[];
 };