feat(ui): stabilize shared M4.8 review viewer

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

@@ -326,6 +326,47 @@ test("spatial timeline renders synchronized accumulation and playback controls",
   assert.equal((markup.match(/type="range"/g) ?? []).length, 2);
 });
 
+test("recorded observation timeline uses compact icon transport and one inline rate trigger", () => {
+  const idleMarkup = renderToStaticMarkup(createElement(ObservationTimeline, {
+    active: true,
+    sourceCount: 2,
+    mode: "recorded",
+    seekable: true,
+    rangeNs: { min: 0, max: 20_000_000_000 },
+    currentNs: 5_000_000_000,
+    playing: false,
+    playbackRate: 1,
+    onSeek: () => undefined,
+    onPlayingChange: () => undefined,
+    onPlaybackRateChange: () => undefined,
+  }));
+  const playingMarkup = renderToStaticMarkup(createElement(ObservationTimeline, {
+    active: true,
+    sourceCount: 2,
+    mode: "recorded",
+    seekable: true,
+    rangeNs: { min: 0, max: 20_000_000_000 },
+    currentNs: 5_000_000_000,
+    playing: true,
+    playbackRate: 1,
+    onSeek: () => undefined,
+    onPlayingChange: () => undefined,
+    onPlaybackRateChange: () => undefined,
+  }));
+
+  assert.match(idleMarkup, /aria-label="Воспроизвести"/);
+  assert.match(idleMarkup, /lucide-play/);
+  assert.match(idleMarkup, /fill="currentColor"/);
+  assert.match(idleMarkup, /stroke-width="0"/);
+  assert.match(playingMarkup, /aria-label="Пауза"/);
+  assert.match(playingMarkup, /lucide-square/);
+  assert.match(playingMarkup, /fill="currentColor"/);
+  assert.match(idleMarkup, /nodedc-select-inline/);
+  assert.match(idleMarkup, />1×<\/span>/);
+  assert.doesNotMatch(idleMarkup, /nodedc-select-trigger__chevron/);
+  assert.doesNotMatch(idleMarkup, />Воспроизвести<|>Пауза</);
+});
+
 test("Rerun expands only root-relative session recordings onto the current origin", () => {
   assert.equal(
     resolveRerunSourceUrl(