feat: implement damage dummy system, floating UI numbers, and double-barrel shotgun mechanics

ui/floating_damage_text.gd

@@ -0,0 +1,30 @@
+extends Label
+class_name FloatingDamageText
+
+var target_pos: Vector3
+var camera: Camera3D
+var float_offset: float = 0.0
+
+func _ready() -> void:
+	# Setup Tween for floating up and fading out
+	var tween = create_tween()
+	tween.set_parallel(true)
+	# Float up 100 pixels
+	tween.tween_property(self, "float_offset", 100.0, 1.0)
+	# Fade out
+	tween.tween_property(self, "modulate:a", 0.0, 1.0)
+	
+	tween.chain().tween_callback(queue_free)
+
+func _process(_delta: float) -> void:
+	if not is_instance_valid(camera):
+		queue_free()
+		return
+		
+	if camera.is_position_behind(target_pos):
+		visible = false
+	else:
+		visible = true
+		var screen_pos = camera.unproject_position(target_pos)
+		# Center the label on the point, then subtract the float offset (moving up on screen)
+		position = screen_pos - size / 2.0 + Vector2(0, -float_offset)