refactor: fix bugs and improve architecture

- Fix double-execution bug in LevelStateHandler (coins/skills were committed twice per level)
- Fix DamageComponent to track multiple targets via HashSet instead of single node
- Fix HealthComponent: update health immediately, decouple from PlayerController via signal wiring in PlayerController
- Remove dead loop in SkillManager.RemoveSkill; simplify O(n²) throw skill loop
- Replace GetNode<T>(path) with .Instance across managers; add Instance to StatisticsManager/SpeedRunManager
- GameManager.GetPlayer() now uses EventBus.PlayerSpawned instead of scanning all scene nodes
- UIManager.UiStack: remove [Export], use private List<Control>
- PlayerState: extract DefaultLives constant, simplify CreateDefault()

scripts/components/DamageComponent.cs

@@ -11,7 +11,7 @@ public partial class DamageComponent : Node
     [Export] public StatusEffectDataResource StatusEffectData { get; set; }
     [Export] public Timer DamageTimer { get; set; }
     
-    private Node _currentTarget = null;
+    private readonly System.Collections.Generic.HashSet<Node> _currentTargets = new();
     private KnockbackComponent _knockbackComponent = null;
     
     [Signal] public delegate void EffectInflictedEventHandler(Node2D target, StatusEffectDataResource effect);
@@ -35,10 +35,11 @@ public partial class DamageComponent : Node
 
     public override void _Process(double delta)
     {
-        if (_currentTarget == null) return;
+        if (_currentTargets.Count == 0) return;
         if (DamageTimer != null) return;
-        
-        ProcessEntityAndApplyDamage(_currentTarget as Node2D);
+
+        foreach (var target in _currentTargets)
+            ProcessEntityAndApplyDamage(target as Node2D);
     }
 
     public void DealDamage(HealthComponent target) => target.DecreaseHealth(Damage);
@@ -56,28 +57,28 @@ public partial class DamageComponent : Node
 
     private void OnAreaBodyExited(Node2D body)
     {
-        if (body != _currentTarget) return;
-        _currentTarget = null;
-        DamageTimer?.Stop();
+        _currentTargets.Remove(body);
+        if (_currentTargets.Count == 0)
+            DamageTimer?.Stop();
     }
 
     private void OnAreaBodyEntered(Node2D body)
     {
-        _currentTarget = body;
+        _currentTargets.Add(body);
 
         if (!CheckIfProcessingIsOn())
             return;
 
-        DamageTimer?.Start();
+        if (_currentTargets.Count == 1)
+            DamageTimer?.Start();
 
         ProcessEntityAndApplyDamage(body);
     }
-    
+
     private void OnDamageTimerTimeout()
     {
-        if (_currentTarget == null) return;
-        
-        ProcessEntityAndApplyDamage(_currentTarget as Node2D);
+        foreach (var target in _currentTargets)
+            ProcessEntityAndApplyDamage(target as Node2D);
     }
     
     private void ProcessEntityAndApplyDamage(Node2D body)

scripts/components/HealthComponent.cs

@@ -1,6 +1,4 @@
-using System.Threading.Tasks;
 using Godot;
-using Mr.BrickAdventures;
 using Mr.BrickAdventures.Autoloads;
 
 namespace Mr.BrickAdventures.scripts.components;
@@ -20,27 +18,16 @@ public partial class HealthComponent : Node2D
 
     public override void _Ready()
     {
-        _floatingTextManager = GetNode<FloatingTextManager>(Constants.FloatingTextManagerPath);
+        _floatingTextManager = FloatingTextManager.Instance;
     }
 
-    public void SetHealth(float newValue)
-    {
-        _ = ApplyHealthChange(newValue);
-    }
-
-    public void IncreaseHealth(float delta)
-    {
-        _ = ApplyHealthChange(Health + delta);
-    }
-
-    public void DecreaseHealth(float delta)
-    {
-        _ = ApplyHealthChange(Health - delta);
-    }
+    public void SetHealth(float newValue) => ApplyHealthChange(newValue);
+    public void IncreaseHealth(float delta) => ApplyHealthChange(Health + delta);
+    public void DecreaseHealth(float delta) => ApplyHealthChange(Health - delta);
 
     public float GetDelta(float newValue) => newValue - Health;
 
-    private async Task ApplyHealthChange(float newHealth, bool playSfx = true)
+    private void ApplyHealthChange(float newHealth, bool playSfx = true)
     {
         newHealth = Mathf.Clamp(newHealth, 0.0f, MaxHealth);
         var delta = newHealth - Health;
@@ -53,39 +40,19 @@ public partial class HealthComponent : Node2D
         else
             _floatingTextManager?.ShowHeal(delta, GlobalPosition);
 
-        if (playSfx)
-        {
-            if (delta > 0f && HealSfx != null)
-            {
-                HealSfx.Play();
-            }
-            else if (delta < 0f && HurtSfx != null)
-            {
-                HurtSfx.Play();
-                await HurtSfx.ToSignal(HurtSfx, AudioStreamPlayer2D.SignalName.Finished);
-            }
-        }
-
         Health = newHealth;
 
+        if (playSfx)
+        {
+            if (delta > 0f)
+                HealSfx?.Play();
+            else
+                HurtSfx?.Play();
+        }
+
         if (Health <= 0f)
-        {
             EmitSignalDeath();
-            // Emit global event if this is the player
-            if (Owner is PlayerController)
-                EventBus.EmitPlayerDied(GlobalPosition);
-        }
         else
-        {
             EmitSignalHealthChanged(delta, Health);
-            // Emit global events if this is the player
-            if (Owner is PlayerController)
-            {
-                if (delta < 0f)
-                    EventBus.EmitPlayerDamaged(Mathf.Abs(delta), Health, GlobalPosition);
-                else
-                    EventBus.EmitPlayerHealed(delta, Health, GlobalPosition);
-            }
-        }
     }
 }

scripts/components/PlayerController.cs

@@ -2,7 +2,6 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 using Godot;
-using Mr.BrickAdventures;
 using Mr.BrickAdventures.Autoloads;
 
 namespace Mr.BrickAdventures.scripts.components;
@@ -34,8 +33,19 @@ public partial class PlayerController : CharacterBody2D
 
     public override void _Ready()
     {
-        var skillManager = GetNodeOrNull<SkillManager>(Constants.SkillManagerPath);
-        skillManager?.RegisterPlayer(this);
+        SkillManager.Instance?.RegisterPlayer(this);
+
+        // Wire HealthComponent signals to global EventBus events
+        var health = GetNodeOrNull<HealthComponent>("HealthComponent");
+        if (health != null)
+        {
+            health.Death += () => EventBus.EmitPlayerDied(GlobalPosition);
+            health.HealthChanged += (delta, total) =>
+            {
+                if (delta < 0f) EventBus.EmitPlayerDamaged(Mathf.Abs(delta), total, GlobalPosition);
+                else EventBus.EmitPlayerHealed(delta, total, GlobalPosition);
+            };
+        }
 
         _inputHandler = GetNode<PlayerInputHandler>("PlayerInputHandler");
         foreach (var child in MovementAbilitiesContainer.GetChildren())
@@ -49,6 +59,7 @@ public partial class PlayerController : CharacterBody2D
 
         _ = ConnectJumpAndGravityAbilities();
         EmitSignalMovementAbilitiesChanged();
+        EventBus.EmitPlayerSpawned(this);
     }
 
     public override void _PhysicsProcess(double delta)