feat: Ensure stone layer chunks always render and remain visible

js/world.js

@@ -527,9 +527,14 @@ function generateChunksAroundPlayer() {
         const chunkY = 1; // The chunk at y = 1 (moved from y = -1)
         const key = getChunkKey(chunkX, chunkY);
         
-        // Always generate and mark as dirty to ensure rendering
+        // Always generate stone layer chunks
         getOrCreateChunk(chunkX, chunkY);
-        dirtyChunks.add(key);
+        
+        // Mark as dirty only if it's a new chunk or if it's visible
+        if (!chunks.has(key) || visibleChunks.some(chunk => 
+            chunk.chunkX === chunkX && chunk.chunkY === chunkY && chunk.isVisible)) {
+            dirtyChunks.add(key);
+        }
     }
     
     // Generate visible chunks first