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

apps/docs/content/(01-linear-structures)/hash-table/347-top-k-frequent-elements.mdx

@@ -1,7 +1,7 @@
 ---
 title: '347. Top K Frequent Elements'
 description: Given an integer array nums and an integer k, return the k most frequent elements. You may return the answer in any order
-icon: line-dot-left-horizontal
+icon: dot
 sidebar:
   label: 'Top K Frequent Elements'
   badge: 'Medium'