Implements modifier and stats system

Adds a modifier and stats system to manage combat-related attributes.

Introduces StatsComponent for storing entity statistics and ModifierManager for applying dynamic modifiers. Recalculates stats based on modifier type and priority.

Updates projectile and weapon components to utilize the new stats system.

combat/projectiles/rock/RockProjectile.tscn

@@ -4,9 +4,3 @@
 
 [node name="RockProjectile" type="Node2D"]
 script = ExtResource("1_8myby")
-speed = null
-damage = null
-lifetime = null
-direction = null
-target_position = null
-is_friendly = null

combat/projectiles/rock/scripts/rock_projectile.gd

@@ -5,7 +5,7 @@ func _ready():
 	lifetime_timer = Timer.new()
 	add_child(lifetime_timer)
 	lifetime_timer.one_shot = true
-	lifetime_timer.wait_time = lifetime
+	lifetime_timer.wait_time = stats.lifetime
 	lifetime_timer.connect("timeout", _on_lifetime_timeout)
 	lifetime_timer.start()
 
@@ -13,7 +13,19 @@ func _ready():
 	connect("body_entered", _on_body_entered)
 
 func _physics_process(delta):
-	position += direction * speed * delta
+	position += direction * stats.speed * delta
+
+func _on_body_entered(body):
+	if body.is_in_group("enemies"):
+		body.take_damage(stats.damage)
+
+		## Check if the projectile is piercing
+		if not get_stat("pierce_count"):
+			# If not piercing, destroy the projectile
+			destroy()
+		else:
+			# If piercing, reduce the pierce count
+			set_stat("pierce_count", get_stat("pierce_count") - 1)
 
 func _on_lifetime_timeout():
 	super._on_lifetime_timeout()