Store chunk tile data as a dense minified grid instead of per-tile objects

Cuts the six overworld chunk JSON files from 146KB to 10KB by replacing
{"pos":[x,y,z],"type":t,"tile":u} entries with a fixed 256-slot array
(index x + y*16, value null or [type, z]) and dropping pretty-printing.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

src/dusk/asset/loader/chunk/assetchunkloader.c

@@ -54,9 +54,11 @@ static bool_t assetChunkTilesHaveTerrain(const tile_t *tiles) {
   return false;
 }
 
-// Reads the "tiles" array - one quad's worth of column data per entry,
-// last one in the array wins per (x, y) column - matching
-// tools/asset/chunk/__main__.py:390-403.
+// Reads the "tiles" array - a dense, fixed-size CHUNK_TILE_COUNT grid,
+// one slot per (x, y) column at index x + y * CHUNK_WIDTH (position is
+// implicit in the index, not stored). Each slot is either `null` (empty
+// column, already zeroed = TILE_SHAPE_NULL) or a 2-element [type, z]
+// array.
 static void assetChunkParseTiles(yyjson_val *root, tile_t *tiles) {
   memoryZero(tiles, CHUNK_TILE_COUNT * sizeof(tile_t));
 
@@ -66,18 +68,12 @@ static void assetChunkParseTiles(yyjson_val *root, tile_t *tiles) {
   size_t idx, len;
   yyjson_val *tileVal;
   yyjson_arr_foreach(tilesArr, idx, len, tileVal) {
-    yyjson_val *posArr = yyjson_obj_get(tileVal, "pos");
-    if(!yyjson_is_arr(posArr) || yyjson_arr_size(posArr) < 3) continue;
+    if(idx >= CHUNK_TILE_COUNT) break;
+    if(!yyjson_is_arr(tileVal) || yyjson_arr_size(tileVal) < 2) continue;
 
-    int32_t x = (int32_t)yyjson_get_int(yyjson_arr_get(posArr, 0));
-    int32_t y = (int32_t)yyjson_get_int(yyjson_arr_get(posArr, 1));
-    int32_t z = (int32_t)yyjson_get_int(yyjson_arr_get(posArr, 2));
-    if(x < 0 || x >= CHUNK_WIDTH || y < 0 || y >= CHUNK_HEIGHT) continue;
-
-    int32_t type = (int32_t)yyjson_get_int(yyjson_obj_get(tileVal, "type"));
-    tiles[x + y * CHUNK_WIDTH] = (tile_t){
-      .shape = (tileshape_t)type, .z = (uint8_t)z
-    };
+    int32_t type = (int32_t)yyjson_get_int(yyjson_arr_get(tileVal, 0));
+    int32_t z = (int32_t)yyjson_get_int(yyjson_arr_get(tileVal, 1));
+    tiles[idx] = (tile_t){ .shape = (tileshape_t)type, .z = (uint8_t)z };
   }
 }