chore(k1): checkpoint connection recovery work

apps/control-station/test/rerunViewportAtomicAdmission.test.mjs

@@ -9,6 +9,7 @@ let claimExclusiveLiveViewer;
 let createRecordedOpenWatchdog;
 let createReentrantViewerDisposer;
 let isLiveRerunPresentationReady;
+let liveTimelineNeedsSynchronization;
 let liveRerunReceiverBindingIdentity;
 let recordedOpenWatchdogTimeoutMs;
 let rerunViewerInitialSource;
@@ -26,6 +27,7 @@ before(async () => {
     createRecordedOpenWatchdog,
     createReentrantViewerDisposer,
     isLiveRerunPresentationReady,
+    liveTimelineNeedsSynchronization,
     liveRerunReceiverBindingIdentity,
     recordedOpenWatchdogTimeoutMs,
     rerunViewerInitialSource,
@@ -82,6 +84,14 @@ test("live presentation waits for the exact receiver to expose a usable range",
   assert.equal(isLiveRerunPresentationReady(true, { min: 1, max: 1 }, 1), true);
 });
 
+test("live timeline is retried only after stream_time exists and until it is active", () => {
+  assert.equal(liveTimelineNeedsSynchronization(false, undefined, { min: 1, max: 2 }), false);
+  assert.equal(liveTimelineNeedsSynchronization(true, undefined, null), false);
+  assert.equal(liveTimelineNeedsSynchronization(true, undefined, { min: 1, max: 2 }), true);
+  assert.equal(liveTimelineNeedsSynchronization(true, "log_time", { min: 1, max: 2 }), true);
+  assert.equal(liveTimelineNeedsSynchronization(true, "stream_time", { min: 1, max: 2 }), false);
+});
+
 test("live receiver binding stays stable across recovery authority projections", () => {
   const sourceUrl = "rerun+http://127.0.0.1:9877/proxy";
   const streamId = "acq-001";
@@ -217,7 +227,11 @@ test("recorded RRD bytes are never split across LogChannel.send_rrd calls", asyn
   );
   assert.match(
     source,
-    /const readyToRender = followLive\s*\? isLiveRerunPresentationReady\(/,
+    /const readyToRender = followLive\s*\? liveTimelineSynchronized && isLiveRerunPresentationReady\(/,
+  );
+  assert.match(
+    source,
+    /viewer\.get_active_timeline\(event\.recording_id\)[\s\S]*viewer\.set_active_timeline\(event\.recording_id, timeline\)/,
   );
   assert.match(
     source,
@@ -257,7 +271,16 @@ test("raw replay exercises the same streaming receiver lifecycle as a live scan"
     new URL("../src/workspaces/Workspaces.tsx", import.meta.url),
     "utf8",
   );
-  assert.match(source, /followLive=\{!recordedReplay && streamActive\}/);
+  assert.match(
+    source,
+    /const liveRerunSource = !recordedSource && \/\^rerun\\\+https\?:\\\/\\\//,
+  );
+  assert.match(
+    source,
+    /const livePresentationActivitySequence = metrics\?\.publishedFrameCount \?\?[\s\S]*liveRerunSource && !streamActive \? 1 : null/,
+  );
+  assert.match(source, /followLive=\{liveRerunSource\}/);
+  assert.match(source, /liveActivitySequence=\{livePresentationActivitySequence\}/);
   assert.match(
     source,
     /sourceUrl\.trim\(\) && pointCloudVisible && !intentionalSourceEnd/,