fix(room): add access check to ws_universal subscribe and fix stream handling

- Add `check_room_access` before `manager.subscribe()` in ws_universal
  to prevent unauthorized room subscription (security fix)
- Fix busy-wait in `poll_push_streams`: sleep 50ms when streams are
  empty, yield only when there are active streams
- Re-subscribe dead rooms after stream errors so events are not
  permanently lost until manual reconnect
- Fix streaming message placeholder using fake content as room_id:
  use chunk.room_id from backend instead
- Show toast error on history load failures instead of silent fallback

libs/api/room/ws_handler.rs

@@ -15,6 +15,10 @@ impl WsRequestHandler {
         Self { service, user_id }
     }
 
+    pub fn service(&self) -> &Arc<AppService> {
+        &self.service
+    }
+
     pub async fn handle(&self, request: WsRequest) -> WsResponse {
         let request_id = request.request_id;
         let action_str = request.action.to_string();

libs/api/room/ws_universal.rs

@@ -10,6 +10,7 @@ use uuid::Uuid;
 
 use crate::error::ApiError;
 use queue::{ReactionGroup, RoomMessageEvent, RoomMessageStreamChunkEvent};
+use room::connection::RoomConnectionManager;
 use service::AppService;
 
 use super::ws::validate_origin;
@@ -195,7 +196,7 @@ pub async fn ws_universal(
                     let _ = session.close(Some(actix_ws::CloseCode::Normal.into())).await;
                     break;
                 }
-                push_event = poll_push_streams(&mut push_streams) => {
+                push_event = poll_push_streams(&mut push_streams, &manager, user_id) => {
                     match push_event {
                         Some(WsPushEvent::RoomMessage { room_id, event }) => {
                             let payload = serde_json::json!({
@@ -294,6 +295,12 @@ pub async fn ws_universal(
                                     match request.action {
                                         WsAction::SubscribeRoom => {
                                             if let Some(room_id) = request.params().room_id {
+                                                // Verify user has access to this room before subscribing
+                                                if let Err(e) = handler.service().room.check_room_access(room_id, user_id).await {
+                                                    let _ = session.text(serde_json::to_string(&WsResponse::error_response(
+                                                        request.request_id, &action_str, 403, "access_denied", &format!("{}", e)
+                                                    )).unwrap_or_default()).await;
+                                                } else {
                                                     match manager.subscribe(room_id, user_id).await {
                                                         Ok(rx) => {
                                                             let stream_rx = manager.subscribe_room_stream(room_id).await;
@@ -308,10 +315,11 @@ pub async fn ws_universal(
                                                         }
                                                         Err(e) => {
                                                             let _ = session.text(serde_json::to_string(&WsResponse::error_response(
-                                                            request.request_id, &action_str, 403, "subscribe_failed", &format!("{}", e)
+                                                                request.request_id, &action_str, 500, "subscribe_failed", &format!("{}", e)
                                                             )).unwrap_or_default()).await;
                                                         }
                                                     }
+                                                }
                                             } else {
                                                 let _ = session.text(serde_json::to_string(&WsResponse::error_response(
                                                     request.request_id, &action_str, 400, "bad_request", "room_id required"
@@ -361,9 +369,15 @@ pub async fn ws_universal(
     Ok(response)
 }
 
-async fn poll_push_streams(streams: &mut PushStreams) -> Option<WsPushEvent> {
+async fn poll_push_streams(
+    streams: &mut PushStreams,
+    manager: &Arc<RoomConnectionManager>,
+    user_id: Uuid,
+) -> Option<WsPushEvent> {
     loop {
         let room_ids: Vec<Uuid> = streams.keys().copied().collect();
+        let mut dead_rooms: Vec<Uuid> = Vec::new();
+
         for room_id in room_ids {
             if let Some((msg_stream, chunk_stream)) = streams.get_mut(&room_id) {
                 tokio::select! {
@@ -380,12 +394,7 @@ async fn poll_push_streams(streams: &mut PushStreams) -> Option<WsPushEvent> {
                                 return Some(WsPushEvent::RoomMessage { room_id, event });
                             }
                             Some(Err(_)) | None => {
-                                // Stream closed/error — remove and re-subscribe to avoid
-                                // spinning on a closed stream. The manager keeps the
-                                // broadcast sender alive so re-subscribing gets the latest
-                                // receiver. Multiple rapid errors are handled by the
-                                // manager's existing retry/cleanup logic.
-                                streams.remove(&room_id);
+                                dead_rooms.push(room_id);
                             }
                         }
                     }
@@ -395,19 +404,34 @@ async fn poll_push_streams(streams: &mut PushStreams) -> Option<WsPushEvent> {
                                 return Some(WsPushEvent::AiStreamChunk { room_id, chunk });
                             }
                             Some(Err(_)) | None => {
-                                streams.remove(&room_id);
+                                dead_rooms.push(room_id);
                             }
                         }
                     }
                 }
             }
         }
+
+        // Re-subscribe dead rooms so we don't permanently lose events
+        for room_id in dead_rooms {
+            if streams.remove(&room_id).is_some() {
+                if let Ok(rx) = manager.subscribe(room_id, user_id).await {
+                    let stream_rx = manager.subscribe_room_stream(room_id).await;
+                    streams.insert(room_id, (
+                        BroadcastStream::new(rx),
+                        BroadcastStream::new(stream_rx),
+                    ));
+                }
+            }
+        }
+
         if streams.is_empty() {
-            tokio::time::sleep(std::time::Duration::from_millis(50)).await;
-            return None;
-        }
+            // Yield so the caller can drop us before the next iteration
+            tokio::time::sleep(Duration::from_millis(50)).await;
+        } else {
             tokio::task::yield_now().await;
         }
+    }
 }
 
 fn extract_user_id_from_token(token: &str) -> Option<Uuid> {

src/hooks/useRoomWs.ts

@@ -1,4 +1,5 @@
 import { useCallback, useEffect, useMemo, useRef, useState } from 'react';
+import { toast } from 'sonner';
 import {
   type AiStreamChunkPayload,
   type RoomMessagePayload,
@@ -176,7 +177,7 @@ export function useRoomWs({
   membersRef.current = members;
 
   /** Ref for AI streaming RAF batch */
-  const streamingBatchRef = useRef<Map<string, { content: string; done: boolean }>>(new Map());
+  const streamingBatchRef = useRef<Map<string, { content: string; done: boolean; room_id: string }>>(new Map());
   const streamingRafRef = useRef<number | null>(null);
 
   /** Flush streaming batch to state */
@@ -193,7 +194,7 @@ export function useRoomWs({
         if (idx === -1) {
           const placeholder: UiMessage = {
             id: messageId,
-            room_id: chunk.content.split('\n')[0]?.slice(0, 100) || '',
+            room_id: chunk.room_id ?? next.find(() => true)?.room_id ?? '',
             sender_type: 'ai',
             content: chunk.done ? chunk.content : '',
             content_type: 'text',
@@ -322,6 +323,7 @@ export function useRoomWs({
             streamingBatchRef.current.set(chunk.message_id, {
               content: chunk.content,
               done: chunk.done,
+              room_id: chunk.room_id,
             });
 
             if (streamingRafRef.current == null) {
@@ -442,6 +444,7 @@ export function useRoomWs({
             })
             .catch(() => {
               if (activeRoomIdRef.current !== roomId) return;
+              toast.error('Failed to load message history');
               setIsHistoryLoaded(true);
             });
         }
@@ -525,7 +528,8 @@ export function useRoomWs({
           return [...newOnes, ...prev];
         });
       } catch {
-        // Non-critical — just stop trying
+        // Non-critical — show toast so user knows the load failed
+        toast.error('Failed to load more messages');
         setIsHistoryLoaded(true);
       } finally {
         setIsLoadingMore(false);