fix(lab): align spatial replay controls

apps/control-station/src/components/ObservationTimeline.tsx

@@ -14,6 +14,7 @@ export function ObservationTimeline({
   onSeek,
   onPlayingChange,
   onJumpToEnd,
+  showJumpToEnd = true,
   playbackRate,
   onPlaybackRateChange,
   accumulationSeconds,
@@ -32,6 +33,7 @@ export function ObservationTimeline({
   onSeek?: (timeNs: number) => void;
   onPlayingChange?: (playing: boolean) => void;
   onJumpToEnd?: () => void;
+  showJumpToEnd?: boolean;
   playbackRate?: number;
   onPlaybackRateChange?: (rate: number) => void;
   accumulationSeconds?: number;
@@ -144,15 +146,17 @@ export function ObservationTimeline({
             {buffered ? `${sourceCount} каналов` : `${synchronizationLabel} · буфер не включён`}
           </small>
         </div>
-        <button
-          type="button"
-          className="observation-timeline__follow"
-          data-active={!buffered && active ? "true" : undefined}
-          disabled={buffered ? !onJumpToEnd : true}
-          onClick={onJumpToEnd}
-        >
-          {buffered ? "К КОНЦУ" : "ЭФИР"}
-        </button>
+        {showJumpToEnd ? (
+          <button
+            type="button"
+            className="observation-timeline__follow"
+            data-active={!buffered && active ? "true" : undefined}
+            disabled={buffered ? !onJumpToEnd : true}
+            onClick={onJumpToEnd}
+          >
+            {buffered ? "К КОНЦУ" : "ЭФИР"}
+          </button>
+        ) : null}
       </div>
     </div>
   );