fix(k1): keep live viewer on stream edge

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

@@ -10,6 +10,7 @@ let createRecordedOpenWatchdog;
 let createReentrantViewerDisposer;
 let recordedOpenWatchdogTimeoutMs;
 let rerunViewerInitialSource;
+let rerunViewerOpenOptions;
 let resolveRecordedViewerSourceUrl;
 
 before(async () => {
@@ -24,6 +25,7 @@ before(async () => {
     createReentrantViewerDisposer,
     recordedOpenWatchdogTimeoutMs,
     rerunViewerInitialSource,
+    rerunViewerOpenOptions,
     resolveRecordedViewerSourceUrl,
   } = await server.ssrLoadModule("/src/components/RerunViewport.tsx"));
 });
@@ -63,6 +65,11 @@ test("only the canonical digest-bound generation URL reaches the native Rerun re
   }
 });
 
+test("only the live receiver opens on the native following edge", () => {
+  assert.deepEqual(rerunViewerOpenOptions(true), { follow_if_http: true });
+  assert.equal(rerunViewerOpenOptions(false), null);
+});
+
 test("recorded admission watchdog is size-aware and exits an incomplete load", () => {
   const smallDelay = recordedOpenWatchdogTimeoutMs(4);
   const currentDelay = recordedOpenWatchdogTimeoutMs(246_331_680);
@@ -170,6 +177,7 @@ test("recorded RRD bytes are never split across LogChannel.send_rrd calls", asyn
   assert.doesNotMatch(source, /missioncore\/recorded-recording/);
   assert.doesNotMatch(source, /recordedChannel/);
   assert.match(source, /viewer\.start\(\s*rerunViewerInitialSource\(resolvedSource\)/s);
+  assert.match(source, /rerunViewerOpenOptions\(followLive\)/);
   assert.match(
     source,
     /recordingOpened = true;[\s\S]*diagnosticLifecycle\.markAdmitted\(\);/,