Add new PNG images for clean and preview outputs

- Added `image_clean.png` to the output directory for the clean image representation.
- Added `image_clean_preview.png` for the preview of the clean image.
- Introduced `image_svg_clean.png` for the SVG clean image representation.

units/bomb.py

@@ -123,6 +123,9 @@ class Explosion(Bomb):
             self.die()
             
     def draw(self):
+        if self.game.map.is_tunnel(*self.position):
+            return
+
         image = self.game.assets["BMP_EXPLOSION"]
         image_size = self.game.render_engine.get_image_size(image)
         partial_x, partial_y = 0, 0