Fix entity id size to fit the entity count

dod.c

@@ -21,7 +21,7 @@ enum EntityTag {
 
 typedef struct Entity Entity;
 struct Entity {
-  u16 id;
+  u32 id;
 };
 
 typedef struct Position Position;
@@ -137,7 +137,7 @@ void init_manager(const Allocator *allocator, Manager *manager) {
   assert(allocator != NULL && manager != NULL);
 
   u64 total_count = (u64)WANDERER_COUNT + (u64)ZONE_COUNT;
-  total_count    += 4 - (total_count % 4);
+  assert(total_count < (1lu << 32)); // Ensure we're not exceeding the maximum limit of entities
 
   u64 entities_size   = sizeof(Entity)   * total_count;
   u64 rects_size      = sizeof(Rect)     * total_count;