feat(web): add spaces, grouped channels and file chat

web/src/features/channel/SideRail.tsx

@@ -11,8 +11,7 @@ interface Props {
 
 /** 电脑右侧的设备与分享:低频,默认收成窄栏,需要时展开 */
 export function SideRail({ open, qrOpen, onToggle }: Props) {
-  const online = useWorkspace((s) => s.devices.filter((d) => d.online).length);
-  const seats = useWorkspace((s) => s.channel?.seats);
+  const channel = useWorkspace((s) => s.channel);
 
   if (open) {
     return (
@@ -29,9 +28,9 @@ export function SideRail({ open, qrOpen, onToggle }: Props) {
   return (
     <aside className={styles.rail}>
       <Button variant="ghost" icon="chevronLeft" label="展开设备与分享" onClick={onToggle} />
-      <span className={styles.count} title="在线设备">
-        <span className={styles.dot} />
-        {online}/{seats}
+      <span className={styles.count} title="已加入席位 / 总席位">
+        {channel?.seatsUsed ?? '—'}/{channel?.seats ?? '—'}
+        <span className={styles.countLabel}>席位</span>
       </span>
       <Button variant="ghost" icon="share" label="分享" onClick={onToggle} />
     </aside>