Debug view improvements, warp animation

* Add a visible frame one tile beyond the normal screen in debug mode.

* Fix the display of motion paths for mounted traps in debug mode.

* Add an animation for the warp trap.

game/player.py

@@ -267,4 +267,6 @@ class Player:
 
     # --- rendering -----------------------------------------------------------
     def draw(self, surface, assets):
-        surface.blit(assets.get("player", self.rect.w, self.rect.h), self.rect)
+        ox, oy = self.level.render_offset
+        surface.blit(assets.get("player", self.rect.w, self.rect.h),
+                     self.rect.move(ox, oy))