Fix weapon position, scale, switch to GLB imports

- Reduced weapon scale 10-13x (previously OBJ models at native size)
- Adjusted on-screen position for each weapon type
- Switched from OBJ to GLB imports (better pivot points)
- Fixed Revolver model coordinate issue

assets/quaternius/weapons/rifle.tscn

@@ -1,5 +1,8 @@
 [gd_scene format=3]
-[ext_resource type="ArrayMesh" path="res://assets/quaternius/models/Rifle.obj" id="1"]
 
-[node name="Rifle" type="MeshInstance3D"]
-mesh = ExtResource("1")
+[ext_resource type="PackedScene" path="res://assets/quaternius/models/Rifle.glb" id="1"]
+
+[node name="Rifle" type="Node3D"]
+scale = Vector3(0.3, 0.3, 0.3)
+
+[node name="Model" parent="." instance=ExtResource("1")]