Implement comprehensive experience and leveling system

**NEW FEATURES:**
- Complete EXP system with Pokemon-style stat calculation
- Level-based stat growth and automatic HP restoration on level up
- Experience gain from catches and battle victories
- Visual level up notifications with stat increases

**EXPERIENCE SOURCES:**
- Successful catches: 5 EXP × caught pet level
- Wild battle victories: 10 EXP × defeated pet level
- Gym battle victories: 20 EXP × defeated pet level (2x multiplier)

**LEVELING MECHANICS:**
- Cubic growth formula: level³ × 4 - 12 (smooth progression)
- Level cap at 100
- Stats recalculated on level up using Pokemon formulas
- Full HP restoration on level up
- Real-time stat increase display

**EXPERIENCE DISPLAY:**
- \!team command now shows "EXP: X to next" for active pets
- Level up messages show exact stat gains
- Experience awarded immediately after catch/victory

**STAT CALCULATION:**
- HP: (2 × base + 31) × level / 100 + level + 10
- Other stats: (2 × base + 31) × level / 100 + 5
- Progressive growth ensures meaningful advancement

**BATTLE INTEGRATION:**
- EXP awarded after wild battles, gym individual battles, and catches
- Different multipliers for different victory types
- First active pet receives all experience

This creates proper RPG progression where pets grow stronger through gameplay,
encouraging both exploration (catches) and combat (battles) for advancement.

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

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

modules/exploration.py

@@ -212,6 +212,9 @@ class Exploration(BaseModule):
                     for achievement in all_achievements:
                         self.send_message(channel, f"🏆 {nickname}: Achievement unlocked: {achievement['name']}! {achievement['description']}")
                 
+                # Award experience for successful catch
+                await self.award_catch_experience(channel, nickname, player, wild_pet)
+                
                 # Remove encounter
                 if player["id"] in self.bot.active_encounters:
                     del self.bot.active_encounters[player["id"]]
@@ -233,6 +236,9 @@ class Exploration(BaseModule):
         
         # Check for achievements after successful catch
         if "Success!" in result:
+            # Award experience for successful catch
+            await self.award_catch_experience(channel, nickname, player, target_pet)
+            
             type_achievements = await self.game_engine.check_and_award_achievements(player["id"], "catch_type", "")
             total_achievements = await self.game_engine.check_and_award_achievements(player["id"], "catch_total", "")
             
@@ -244,4 +250,32 @@ class Exploration(BaseModule):
         # Remove the encounter regardless of success
         del self.bot.active_encounters[player["id"]]
         
-        self.send_message(channel, f"🎯 {nickname}: {result}")
+        self.send_message(channel, f"🎯 {nickname}: {result}")
+    
+    async def award_catch_experience(self, channel, nickname, player, caught_pet):
+        """Award experience to active pets for successful catch"""
+        active_pets = await self.database.get_active_pets(player["id"])
+        if not active_pets:
+            return
+        
+        # Calculate experience for catch (less than battle victory)
+        base_exp = caught_pet["level"] * 5  # 5 EXP per level for catches
+        
+        # Award to first active pet
+        main_pet = active_pets[0]
+        exp_result = await self.database.award_experience(main_pet["id"], base_exp)
+        
+        if exp_result["success"]:
+            # Display experience gain
+            self.send_message(channel, 
+                f"⭐ {exp_result['pet_name']} gained {exp_result['exp_gained']} EXP for the catch!")
+            
+            # Handle level up
+            if exp_result["leveled_up"]:
+                await self.handle_level_up_display(channel, nickname, exp_result)
+    
+    async def handle_level_up_display(self, channel, nickname, exp_result):
+        """Display level up information (shared with battle system)"""
+        from .battle_system import BattleSystem
+        battle_system = BattleSystem(self.bot, self.database, self.game_engine)
+        await battle_system.handle_level_up_display(channel, nickname, exp_result)