fix(page+bot): 리뷰 지적사항 반영 - 서버 멤버십·같은음성채널 인가(1,2), SSE 공유구독 fan-out(3), botRpc 즉시폴링(4), 큐삭제 encoded 검증(6), 진행바 anchor 타이머(7), 캐시 파싱 가드(8), key 안정화(9), 볼륨 롤백(10), SSE 자동재연결(11), body userId 정리(12)

page/src/components/player/MainContent.tsx

@@ -55,7 +55,7 @@ export default function MainContent({
     }
 
     let endpoint = "";
-    const bodyData: Record<string, unknown> = { serverId: selectedServer.id, userId };
+    const bodyData: Record<string, unknown> = { serverId: selectedServer.id };
     if (actionType === 'player_play') {
       endpoint = "/api/player/play";
       bodyData.track = track;
@@ -108,8 +108,16 @@ export default function MainContent({
       setIsFetching(true);
       const cached = sessionStorage.getItem("filtered_servers");
       if (cached) {
-        setServers(JSON.parse(cached));
-        setIsFetching(false);
+        try {
+          const parsed = JSON.parse(cached);
+          if (Array.isArray(parsed)) {
+            setServers(parsed);
+            setIsFetching(false);
+          }
+        } catch {
+          // 캐시 손상 시 무시하고 아래 fetch로 새로 받는다.
+          sessionStorage.removeItem("filtered_servers");
+        }
       }
 
       fetch("/api/servers")
@@ -162,7 +170,7 @@ export default function MainContent({
   const hasAnyResults = searchResults.spotify.length > 0 || searchResults.youtubeMusic.length > 0 || searchResults.youtubeVideo.length > 0;
 
   const renderTrackCard = (track: SearchTrack) => (
-    <div key={track.videoId || track.id} className="bg-neutral-800/40 p-3 rounded-xl hover:bg-neutral-800 transition-all group border border-transparent hover:border-neutral-700 shadow-md w-full">
+    <div key={track.videoId || track.id || track.url || track.title} className="bg-neutral-800/40 p-3 rounded-xl hover:bg-neutral-800 transition-all group border border-transparent hover:border-neutral-700 shadow-md w-full">
       <div className="aspect-square bg-neutral-700 rounded-md mb-2 relative overflow-hidden shadow-lg">
         {track.thumbnail && <img src={track.thumbnail} className="w-full h-full object-cover" alt={track.title} />}
         <button