Add \!heal command and automatic pet recovery background system

- Implement \!heal command with 1-hour cooldown available to all users
- Add comprehensive cooldown tracking with database last_heal_time validation
- Heal command restores all active pets to full health
- Add background pet recovery system to game engine:
  - Automatic 30-minute recovery timer for fainted pets
  - Background task checks every 5 minutes for eligible pets
  - Auto-recovery restores pets to 1 HP after 30 minutes
  - Proper startup/shutdown integration with game engine
- Add pet_recovery_task to game engine with graceful shutdown
- Include detailed logging for recovery operations
- Ensure system resilience with error handling and task cancellation

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/game_engine.py

@@ -16,6 +16,7 @@ class GameEngine:
         self.type_chart = {}
         self.weather_patterns = {}
         self.weather_task = None
+        self.pet_recovery_task = None
         self.shutdown_event = asyncio.Event()
     
     async def load_game_data(self):
@@ -28,6 +29,7 @@ class GameEngine:
         await self.database.initialize_gyms()
         await self.init_weather_system()
         await self.battle_engine.load_battle_data()
+        await self.start_pet_recovery_system()
     
     async def load_pet_species(self):
         try:
@@ -705,7 +707,58 @@ class GameEngine:
         else:
             return f"🐾 {pet_name}"
     
+    async def start_pet_recovery_system(self):
+        """Start the background pet recovery task"""
+        if self.pet_recovery_task is None or self.pet_recovery_task.done():
+            print("🏥 Starting pet recovery background task...")
+            self.pet_recovery_task = asyncio.create_task(self._pet_recovery_loop())
+    
+    async def stop_pet_recovery_system(self):
+        """Stop the background pet recovery task"""
+        print("🏥 Stopping pet recovery background task...")
+        if self.pet_recovery_task and not self.pet_recovery_task.done():
+            self.pet_recovery_task.cancel()
+            try:
+                await self.pet_recovery_task
+            except asyncio.CancelledError:
+                pass
+    
+    async def _pet_recovery_loop(self):
+        """Background task that checks for pets eligible for auto-recovery"""
+        try:
+            while not self.shutdown_event.is_set():
+                try:
+                    # Check every 5 minutes for pets that need recovery
+                    await asyncio.sleep(300)  # 5 minutes
+                    
+                    if self.shutdown_event.is_set():
+                        break
+                    
+                    # Get pets eligible for auto-recovery (fainted for 30+ minutes)
+                    eligible_pets = await self.database.get_pets_for_auto_recovery()
+                    
+                    if eligible_pets:
+                        print(f"🏥 Auto-recovering {len(eligible_pets)} pet(s) after 30 minutes...")
+                        
+                        for pet in eligible_pets:
+                            success = await self.database.auto_recover_pet(pet["id"])
+                            if success:
+                                print(f"  🏥 Auto-recovered {pet['nickname'] or pet['species_name']} (ID: {pet['id']}) to 1 HP")
+                            else:
+                                print(f"  ❌ Failed to auto-recover pet ID: {pet['id']}")
+                    
+                except asyncio.CancelledError:
+                    break
+                except Exception as e:
+                    print(f"Error in pet recovery loop: {e}")
+                    # Continue the loop even if there's an error
+                    await asyncio.sleep(60)  # Wait a minute before retrying
+                    
+        except asyncio.CancelledError:
+            print("Pet recovery task cancelled")
+    
     async def shutdown(self):
         """Gracefully shutdown the game engine"""
         print("🔄 Shutting down game engine...")
-        await self.stop_weather_system()
+        await self.stop_weather_system()
+        await self.stop_pet_recovery_system()