refactor(viewer): profile rerun loading by playback stage

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

@@ -11,6 +11,7 @@ let isRecordedPlaybackPresentationReady;
 let isUsableRecordedPlaybackRange;
 let recordedPlaybackBufferState;
 let recordedPlaybackRangeWhenReady;
+let rerunPresentationStatus;
 
 before(async () => {
   server = await createServer({
@@ -26,6 +27,7 @@ before(async () => {
     isUsableRecordedPlaybackRange,
     recordedPlaybackBufferState,
     recordedPlaybackRangeWhenReady,
+    rerunPresentationStatus,
   } = await server.ssrLoadModule("/src/components/RerunViewport.tsx"));
 });
 
@@ -33,7 +35,7 @@ after(async () => {
   await server?.close();
 });
 
-test("a first frame reports buffer telemetry but is not ready for presentation", () => {
+test("a verified first frame is presentable while full-range controls stay closed", () => {
   assert.equal(isUsableRecordedPlaybackRange(null), false);
   assert.equal(isUsableRecordedPlaybackRange({ min: Number.NaN, max: 0 }), false);
   assert.equal(isUsableRecordedPlaybackRange({ min: 2, max: 1 }), false);
@@ -47,8 +49,11 @@ test("a first frame reports buffer telemetry but is not ready for presentation",
     bufferProgress: 0,
     fullyBuffered: false,
   });
-  assert.equal(isRecordedPlaybackReady(true, true, firstFrame), false);
+  assert.equal(isRecordedPlaybackReady(true, true, firstFrame), true);
   assert.equal(recordedPlaybackRangeWhenReady({ min: 0, max: 0 }, firstFrame, true), null);
+  assert.equal(rerunPresentationStatus("ready", "loading", true), "ready");
+  assert.equal(rerunPresentationStatus("loading", "ready", true), "loading");
+  assert.equal(rerunPresentationStatus("ready", "error", true), "ready");
 });
 
 test("host timeline remains unmounted until the verified recording is fully ready", () => {
@@ -107,7 +112,7 @@ test("buffer progress grows independently and preserves the full-buffer toleranc
   );
   assert.equal(missingDeclaredStart.bufferProgress, 1);
   assert.equal(missingDeclaredStart.fullyBuffered, false);
-  assert.equal(isRecordedPlaybackReady(true, true, missingDeclaredStart), false);
+  assert.equal(isRecordedPlaybackReady(true, true, missingDeclaredStart), true);
 });
 
 test("a verified split boundary spill covers and clamps the declared LAB window", () => {