perf: abstract reply modal logic into hook for post page and board page

src/hooks/use-reply-modal.ts

@@ -0,0 +1,29 @@
+import { useState, useCallback } from 'react';
+
+const useReplyModal = () => {
+  const [showReplyModal, setShowReplyModal] = useState(false);
+  const [activeCid, setActiveCid] = useState<string | null>(null);
+
+  const openReplyModal = useCallback(
+    (cid: string) => {
+      if (activeCid && activeCid !== cid) {
+        closeModal(); // close modal if a different CID is clicked
+        setActiveCid(cid);
+        setShowReplyModal(true);
+      } else if (!activeCid) {
+        setActiveCid(cid);
+        setShowReplyModal(true);
+      }
+    },
+    [activeCid],
+  );
+
+  const closeModal = useCallback(() => {
+    setActiveCid(null);
+    setShowReplyModal(false);
+  }, []);
+
+  return { showReplyModal, activeCid, openReplyModal, closeModal };
+};
+
+export default useReplyModal;