fix: 교사 토론 종료 시 학생 화면 자동 반영 — 3초 폴링 fragment 추가

fetch_debate_status 캐시가 만료돼도 학생 페이지가 rerun되지 않아
종료 상태가 반영 안 되는 문제 수정.
@st .fragment(run_every=3)으로 3초마다 상태 확인 후 변경 시 전체 rerun.

https://claude.ai/code/session_016DE3uHLsVmA5Uv7gZGGaKT

app.py

@@ -48,6 +48,7 @@ if 'admin_auth' not in st.session_state: st.session_state['admin_auth'] = False
 if 'teacher_id' not in st.session_state: st.session_state['teacher_id'] = ""
 if 'is_working' not in st.session_state: st.session_state['is_working'] = False
 if 'ai_hint_manual_mode' not in st.session_state: st.session_state['ai_hint_manual_mode'] = False
+if '_last_debate_status' not in st.session_state: st.session_state['_last_debate_status'] = None
 
 if st.session_state['page'] != "home":
     col_home_btn, _ = st.columns([1, 7])
@@ -102,6 +103,15 @@ else:
     st.title(f"🎙️ 말자취(Talk-Trace) AI [{room_name}]")
 st.info(f"**현재 주제:** {current_topic} ({current_mode})")
 
+@st.fragment(run_every=3)
+def _poll_debate_status(room_name):
+    """학생 화면에서 3초마다 토론 상태를 확인하고 변경 시 전체 rerun."""
+    current = fetch_debate_status(supabase, room_name)
+    if current != st.session_state.get("_last_debate_status"):
+        st.session_state["_last_debate_status"] = current
+        st.rerun()
+
+
 @st.fragment
 def _render_opinion_input(supabase, room_name, user_role, student_name, student_number, current_mode):
     st.subheader("🗣️ 내 의견 작성")
@@ -202,6 +212,7 @@ def _render_opinion_input(supabase, room_name, user_role, student_name, student_
         st.rerun()
 
 if user_role == "학생" and opinion_changes_available():
+    _poll_debate_status(room_name)
     debate_status = fetch_debate_status(supabase, room_name)
     if debate_status == "ended":
         render_post_opinion_section(supabase, room_name, student_name, act_type, current_topic)