Keep Radio Next and Previous from starting playback before Play

The Next and Previous buttons cycled stations with the layer's default
autoplay, so a first press started buffering a broadcaster stream even
though the panel says audio connects only after Play. Stepping now only
selects until a stream is loading, buffering or playing; once one is,
playback follows the new station so the old broadcaster does not keep
playing under the new label.

The compact Next fallback scenario in qa-radio.mjs started from a stopped
stream and relied on the old behaviour, so it now starts from a playing
station.

Fixes HAL-722

Co-Authored-By: Claude Opus 5.5 <[email protected]>

scripts/qa-radio.mjs

@@ -3820,7 +3820,15 @@ async function main() {
       radio.stopPlayback();
       Array.from({ length: gev.viewer.dataSources.length }, (_, index) => gev.viewer.dataSources.get(index))
         .find((item) => item.name === 'Radio stations').clustering.enabled = true;
-      radio.selectStation('00000000-0000-4000-8000-000000000001', { autoplay: false, focus: false });
+      // Next only carries playback once a stream is active (HAL-722), so the
+      // fallback scenario starts from a playing station.
+      radio.selectStation('00000000-0000-4000-8000-000000000001', { autoplay: true, focus: false });
+    });
+    await page.waitForFunction(() => window.__godsEyeView.dataManager.layers.get('radio').module.getUIState().audioState === 'playing');
+    await page.evaluate(() => {
+      const gev = window.__godsEyeView;
+      const camera = gev.viewer.camera;
+      const radio = gev.dataManager.layers.get('radio').module;
       const pool = gev.styleManager._radioControls._radioTunerPool;
       const selectedIndex = pool.findIndex((station) => station.id === radio.getUIState().selected?.id);
       window.__qaRadioExpectedPrimary = pool[(selectedIndex + 1) % pool.length];