feat: Enhance game mechanics and structure

- Added `ColorBar` class for visual representation of values.
- Expanded `EntityBase` with new properties: `isBoss` and `weapons`, and implemented damage handling and entity generation methods.
- Updated `EntityStateBar` to use `ColorBar` for health representation.
- Introduced `BulletBase` scene and script for bullet mechanics, including damage handling and generation.
- Created `WorldTool` for managing the game world and root node.
- Implemented `EntityTool` for retrieving entities from hurtboxes.
- Added `GameRule` for managing game rules like friendly fire.
- Updated scene files to reflect new structures and added necessary resources.

scripts/Tools/EntityTool.gd

@@ -0,0 +1,10 @@
+class_name EntityTool
+
+static func fromHurtbox(node: Node) -> EntityBase:
+	if node is Area2D:
+		var texture = node.get_parent()
+		if texture is AnimatedSprite2D:
+			var entity = texture.get_parent()
+			if entity is EntityBase:
+				return entity as EntityBase
+	return null