fix(k1): admit live rerun only after real data

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

@@ -275,6 +275,40 @@ export function isUsableRecordedPlaybackRange(
   );
 }
 
+/**
+ * A live receiver is presentable only after the exact browser store exposes
+ * real timeline data that the backend has also confirmed publishing.
+ * `WebViewer.start()` and a non-null active recording id are transport setup,
+ * not evidence that the spatial scene can render.
+ */
+export function isLiveRerunPresentationReady(
+  viewerStarted: boolean,
+  rangeNs: { min: number; max: number } | null,
+  backendActivitySequence: number | null,
+): boolean {
+  return viewerStarted &&
+    Number.isSafeInteger(backendActivitySequence) &&
+    (backendActivitySequence ?? 0) > 0 &&
+    isUsableRecordedPlaybackRange(rangeNs);
+}
+
+/**
+ * Key the native receiver to its data-plane binding. Recovery authority is a
+ * retry fence projected from changing supervisor snapshots; it must not tear
+ * down a healthy WebViewer while this acquisition and URL remain unchanged.
+ */
+export function liveRerunReceiverBindingIdentity(
+  sourceUrl: string,
+  liveStreamId: string | null,
+  followLive: boolean,
+): string {
+  return JSON.stringify([
+    followLive ? "live" : "recorded",
+    sourceUrl.trim(),
+    followLive ? liveStreamId?.trim() ?? "" : "",
+  ]);
+}
+
 /** Describe progressive archive availability without gating first rendering. */
 export function recordedPlaybackBufferState(
   rangeNs: { min: number; max: number } | null,
@@ -938,6 +972,11 @@ export function RerunViewport({
     presentationGate,
     recordedArtifact !== null,
   );
+  const liveReceiverBindingIdentity = liveRerunReceiverBindingIdentity(
+    sourceUrl,
+    liveStreamId,
+    followLive,
+  );
 
   useEffect(() => subscribeToLiveViewerBuildFence(() => {
     uiBuildStaleRef.current = true;
@@ -949,7 +988,7 @@ export function RerunViewport({
 
   useEffect(() => {
     liveRecoveryRef.current = initialLiveReceiverRecoveryState();
-  }, [followLive, liveRecoveryAuthorityIdentity, liveStreamId, sourceUrl]);
+  }, [liveReceiverBindingIdentity]);
 
   useEffect(() => {
     const normalizedSource = sourceUrl.trim();
@@ -1152,9 +1191,10 @@ export function RerunViewport({
           recoveryAttempt: liveRecoveryRef.current.attempts || null,
         });
       }
+      const currentRecoveryAuthorityIdentity = liveRecoveryAuthorityRef.current;
       const recovery = requestLiveReceiverRecovery(liveRecoveryRef.current, {
-        activeAuthorityIdentity: liveRecoveryAuthorityRef.current,
-        expectedAuthorityIdentity: liveRecoveryAuthorityIdentity,
+        activeAuthorityIdentity: currentRecoveryAuthorityIdentity,
+        expectedAuthorityIdentity: currentRecoveryAuthorityIdentity,
         disposed,
       });
       liveRecoveryRef.current = recovery.state;
@@ -1245,7 +1285,7 @@ export function RerunViewport({
         stalledForMs: Math.round(observed.stalledForMs),
         recoveryAttempt: Math.min(
           liveRecoveryRef.current.attempts + 1,
-          liveRecoveryAuthorityIdentity
+          liveRecoveryAuthorityRef.current
             ? Number.MAX_SAFE_INTEGER
             : LIVE_RECEIVER_MAX_RECOVERY_ATTEMPTS,
         ),
@@ -1356,17 +1396,9 @@ export function RerunViewport({
             ) return;
             recordingOpened = true;
             if (!isRecordedSource) {
-              diagnosticLifecycle.markAdmitted();
-              if (liveRecoveryRef.current.awaitingRecovery) {
-                diagnosticLifecycle.post({
-                  eventCode: "live_receiver_recovered",
-                  streamId: liveStreamIdRef.current,
-                  backendActivitySequence: liveActivitySequenceRef.current,
-                  viewerRangeMaxNs: latestLiveRangeMaxNs,
-                  recoveryAttempt: liveRecoveryRef.current.attempts,
-                });
-              }
-              liveRecoveryRef.current = initialLiveReceiverRecoveryState();
+              // Store discovery only establishes a candidate. Admission is
+              // committed below after this recording exposes a usable live
+              // range backed by an actual published frame.
             }
             if (
               recordedBlueprintUrl &&
@@ -1479,7 +1511,11 @@ export function RerunViewport({
                 setRecordingBufferProgress(recordedBuffer.bufferProgress);
               }
               const readyToRender = followLive
-                ? viewerStartResolved
+                ? isLiveRerunPresentationReady(
+                    viewerStartResolved,
+                    rangeNs,
+                    liveActivitySequenceRef.current,
+                  )
                 : isRecordedPlaybackReady(viewerStartResolved, artifactVerified, recordedBuffer);
               const presentationReady = presentationGateRef.current === "ready";
               if (!followLive && (!readyToRender || !presentationReady) && playing) {
@@ -1531,6 +1567,25 @@ export function RerunViewport({
               });
               if (readyToRender && !readyPublished) {
                 readyPublished = true;
+                if (followLive) {
+                  diagnosticLifecycle.post({
+                    eventCode: "live_receiver_active_store_admitted",
+                    streamId: liveStreamIdRef.current,
+                    backendActivitySequence: liveActivitySequenceRef.current,
+                    viewerRangeMaxNs: rangeNs?.max ?? null,
+                  });
+                  diagnosticLifecycle.markAdmitted();
+                  if (liveRecoveryRef.current.awaitingRecovery) {
+                    diagnosticLifecycle.post({
+                      eventCode: "live_receiver_recovered",
+                      streamId: liveStreamIdRef.current,
+                      backendActivitySequence: liveActivitySequenceRef.current,
+                      viewerRangeMaxNs: rangeNs?.max ?? null,
+                      recoveryAttempt: liveRecoveryRef.current.attempts,
+                    });
+                  }
+                  liveRecoveryRef.current = initialLiveReceiverRecoveryState();
+                }
                 if (!followLive) clearRecordedAdmissionWatchdog();
                 if (!followLive) setRecordingBufferProgress(1);
                 recordedSceneAdmitted = true;
@@ -1563,11 +1618,6 @@ export function RerunViewport({
             // Rerun 0.34.1 may ingest an SDK gRPC store without forwarding its
             // recording_open event to the JavaScript wrapper. The active store
             // is the authoritative fallback and avoids hiding a ready canvas.
-            diagnosticLifecycle.post({
-              eventCode: "live_receiver_active_store_admitted",
-              streamId: liveStreamIdRef.current,
-              backendActivitySequence: liveActivitySequenceRef.current,
-            });
             admitRecording({
               application_id: "nodedc_mission_core_spatial",
               recording_id: recordingId,
@@ -1716,10 +1766,8 @@ export function RerunViewport({
     autoplayWhenReady,
     expectedTimelineEndSeconds,
     expectedTimelineStartSeconds,
-      followLive,
+    liveReceiverBindingIdentity,
     initialPlaybackStartSeconds,
-    liveStreamId,
-    liveRecoveryAuthorityIdentity,
     onPlaybackChange,
     onPlaybackControllerChange,
     onSelectionChange,
@@ -1729,7 +1777,6 @@ export function RerunViewport({
     recordedArtifact?.sourceUrl,
     recordedArtifact?.viewerSourceUrl,
     retryNonce,
-    sourceUrl,
   ]);
 
   useEffect(() => {