Fix projectiles and attacks passing through closed doors

Closed doors now block line of sight for both enemy AI and player
weapons. Previously, door tiles were excluded from collision checks,
allowing attacks through them.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

js/enemies.js

@@ -229,7 +229,7 @@ class Enemy {
             const checkY = Math.floor(this.y + stepY * i);
             if (checkY >= 0 && checkY < map.length && checkX >= 0 && checkX < map[0].length) {
                 const cell = map[checkY][checkX];
-                if (cell > 0 && cell !== WALL_DOOR) return false;
+                if (cell > 0) return false;
             }
         }
         return true;