feat: Add lava element with dynamic colors and interactions

index.html

@@ -19,6 +19,7 @@
                 <button id="seed-btn">Seed</button>
                 <button id="tree-seed-btn">Tree Seed</button>
                 <button id="fire-btn">Fire</button>
+                <button id="lava-btn">Lava</button>
                 <button id="eraser-btn">Eraser</button>
             </div>
             <div class="navigation">