docs: replace legacy line‑dot‑left‑horizontal icons with unified dot icon across docs

apps/docs/content/(03-hierarchical)/tree-bfs/1448-count-good-nodes-in-binary-tree.mdx

@@ -1,7 +1,7 @@
 ---
 title: '1448. Count Good Nodes in Binary Tree'
 description: Given a binary tree root, a node X in the tree is named good if in the path from root to X there are no nodes with a value greater than X
-icon: line-dot-left-horizontal
+icon: dot
 sidebar:
   label: 'Count Good Nodes in Binary Tree'
   badge: 'Medium'