Implemented demon enemy combat, enemy knockback, and directional player attacks

- Added Demon enemy scene with detection, pursuit, attack, hurt, and death states
- Configured Demon collision layers, detection area, and attack hitbox
- Fixed Demon movement to pursue player horizontally and attack at close range
- Allowed enemy/player overlap for melee combat encounters
- Added enemy damage and death handling
- Added knockback system for enemies when hit
- Fixed player punch hitbox positioning based on facing direction
- Corrected directional melee attacks so enemies can be hit from both left and right sides
- Fixed collision mask issues affecting floors and enemy detection
- Improved memory piece pickup interaction to support button-based collection
- Continued testing and debugging combat interactions in Graveyard and Demon levels

Scenes/Levels/MainGame.tscn

@@ -2,7 +2,7 @@
 
 [ext_resource type="PackedScene" uid="uid://bu8e4iyw8pc03" path="res://Scenes/Characters/Player.tscn" id="1_d5ayw"]
 [ext_resource type="Script" uid="uid://bs4frobn6kxne" path="res://Scripts/scene_manager.gd" id="2_us1pb"]
-[ext_resource type="PackedScene" uid="uid://bcray1583u4e6" path="res://Scenes/Levels/Level_2_demons.tscn" id="3_d5ayw"]
+[ext_resource type="PackedScene" uid="uid://8n6472fqqmcc" path="res://Scenes/Levels/Level_3_graveyard.tscn" id="3_d5ayw"]
 
 [node name="MainGame" type="Node2D"]
 
@@ -13,4 +13,4 @@ script = ExtResource("2_us1pb")
 
 [node name="CurrentLevel" type="Node2D" parent="."]
 
-[node name="DemonRace" parent="CurrentLevel" instance=ExtResource("3_d5ayw")]
+[node name="Graveyard" parent="CurrentLevel" instance=ExtResource("3_d5ayw")]