fix: viewer.js string entry handling + HLS console log for integration tests

- Handle string entries in createPanel (e.g. 'https://...mp4')
  instead of dropping them as null — restores legacy string URL support.
- Add console.log for HLS detection so integration tests can verify
  HLS playback paths are exercised.

src/viewer/viewer.js

@@ -139,6 +139,7 @@ function createPanel(entry, tag) {
   if (mediaType === 'hls' && hlsManifest) {
     video.dataset.hlsManifest = hlsManifest;
     video.dataset.mediaType = 'hls';
+    console.log('[goon-viewer] HLS detected, manifest:', hlsManifest);
     panel.appendChild(video);
     if (tag) {
       const label = document.createElement('div');
@@ -185,7 +186,7 @@ async function init() {
   const hlsEntries = [];
 
   for (let i = 0; i < totalPanels; i++) {
-    const entry = (typeof videoUrls[i] === 'object') ? videoUrls[i] : null;
+    const entry = (typeof videoUrls[i] === 'object') ? videoUrls[i] : (videoUrls[i] ? { src: videoUrls[i] } : null);
     const { panel, hlsEntry } = createPanel(entry, tags[i]);
     panelsEl.appendChild(panel);
     if (hlsEntry) hlsEntries.push(hlsEntry);