fix: equalize power-up spawn odds, use Math.Max in domain, null-guard Definition

Assets/Scripts/Core/Domain/GameSession.cs

@@ -2,7 +2,6 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using Core.Ports;
-using UnityEngine;
 using Random = System.Random;
 
 namespace Core.Domain
@@ -75,7 +74,7 @@ namespace Core.Domain
             {
                 _npcTimer = 0f;
                 OnSpawnNpc?.Invoke();
-                NpcSpawnTime = Mathf.Max(5f, NpcSpawnTime * 0.95f);
+                NpcSpawnTime = Math.Max(5f, NpcSpawnTime * 0.95f);
             }
 
             _powerUpTimer += deltaTime;
@@ -182,13 +181,13 @@ namespace Core.Domain
 
             var tile = validTiles[_rng.Next(validTiles.Count)];
 
-            var rand = _rng.Next(0, 4);
-            var type = PowerUpType.LightFooted;
+            var rand = _rng.Next(0, 3);
+            PowerUpType type;
             switch (rand)
             {
                 case 0: type = PowerUpType.LightFooted; break;
                 case 1: type = PowerUpType.SpeedBoost; break;
-                case 3: type = PowerUpType.TimeSlow; break;
+                default: type = PowerUpType.TimeSlow; break;
             }
 
             OnSpawnPowerUp?.Invoke(type, tile.Id);

Assets/Scripts/Infrastructure/Unity/GameBootstrap.cs

@@ -65,8 +65,8 @@ namespace Infrastructure.Unity
 
             // Set Theme based on High Score
             ThemeManager.CurrentTheme = ThemeManager.GetTheme(_gameSession.HighScore);
-            
-            var floorsCount = levelGenerator ? levelGenerator.Definition.FloorCount : 1;
+
+            var floorsCount = levelGenerator?.Definition != null ? levelGenerator.Definition.FloorCount : 1;
             
             if (levelGenerator)
             {