fix: 공감 동점 시 같은 등수 뱃지 + 3초 쿨다운 추가

- 같은 공감 수 = 같은 뱃지 (dense rank, 예: 동점 1위 둘 다 🥇)
- 공감 클릭 후 3초간 모든 공감 버튼 비활성화

https://claude.ai/code/session_016DE3uHLsVmA5Uv7gZGGaKT

components/chat_board.py

@@ -1,3 +1,4 @@
+import time
 import streamlit as st
 import plotly.express as px
 from collections import Counter
@@ -9,6 +10,7 @@ from config import DASHBOARD_FETCH_LIMIT, LIVE_BOARD_FETCH_LIMIT, LIVE_REFRESH_I
 
 
 _RANK_BADGES = {1: "🥇", 2: "🥈", 3: "🥉"}
+_LIKE_COOLDOWN = 3
 
 
 def _anon_ip(raw_ip: str) -> str:
@@ -62,6 +64,7 @@ def _live_chat_board_core(supabase, room_name, user_role, teacher_auth, student_
         my_likes = set()
         badge_map = {}
         my_anon_ip = ""
+        on_like_cooldown = False
         if use_likes:
             likes_data = fetch_room_likes(supabase, room_name)
             likes_count = Counter(item['opinion_id'] for item in likes_data)
@@ -69,9 +72,16 @@ def _live_chat_board_core(supabase, room_name, user_role, teacher_auth, student_
             raw_client_ip = get_client_ip()
             if raw_client_ip:
                 my_anon_ip = _anon_ip(raw_client_ip)
-            # 상위 3개 뱃지
-            top3 = [oid for oid, _ in likes_count.most_common(3) if likes_count[oid] > 0]
-            badge_map = {oid: _RANK_BADGES[rank] for rank, oid in enumerate(top3, 1)}
+            # 동점 처리: 같은 공감 수 = 같은 등수 (dense rank)
+            distinct_counts = sorted({c for c in likes_count.values() if c > 0}, reverse=True)[:3]
+            count_to_rank = {c: rank for rank, c in enumerate(distinct_counts, 1)}
+            badge_map = {
+                oid: _RANK_BADGES[count_to_rank[cnt]]
+                for oid, cnt in likes_count.items()
+                if cnt > 0 and cnt in count_to_rank
+            }
+            # 쿨다운 확인
+            on_like_cooldown = (time.time() - st.session_state.get('_last_like_ts', 0)) < _LIKE_COOLDOWN
 
         def delete_chat_msg(msg_id):
             try:
@@ -86,6 +96,7 @@ def _live_chat_board_core(supabase, room_name, user_role, teacher_auth, student_
         def do_toggle_like(msg_id):
             toggle_like(supabase, msg_id, room_name, student_name)
             fetch_room_likes.clear()
+            st.session_state['_last_like_ts'] = time.time()
 
         def render_msg(row):
             formatted_timestamp = format_kst_datetime(row.get("timestamp", ""))
@@ -97,7 +108,7 @@ def _live_chat_board_core(supabase, room_name, user_role, teacher_auth, student_
             # 셀프 공감 차단: 의견 작성자 IP와 현재 사용자 IP 비교
             row_ip = str(row.get("ip_address", "")).strip() if hasattr(row, "get") else ""
             is_self = bool(my_anon_ip and row_ip and my_anon_ip == row_ip)
-            like_disabled = is_self or not use_likes
+            like_disabled = is_self or not use_likes or on_like_cooldown
             like_label = f"👍 {count}" if count > 0 else "👍"
             like_type = "primary" if is_liked else "secondary"