test(ads): [PKG-ADS-02] cover legacy timing and real media contracts

test/browser/README.md

@@ -1,5 +1,11 @@
 # Browser regression entry
 
+`yarn test:browser test/browser/ads.spec.js` tests actual Ads 1.0.6 and candidate code
+with published 5.4.1 and candidate cores using local image/video media. It covers actual
+decoded pixels, countdown, skipping, content restoration, 404 and source replacement.
+Published-only rejection cases inject an exact play failure; they do not certify device
+autoplay policies. See [Ads validation](../../refactor/ads-validation.md).
+
 Audio Track tests use the source and frozen 1.1.0 plugin on both cores. The local AAC fixture
 has a pinned hash and generation command in media/audio-tone.json and uses the existing Range
 server. The suite retains published cleanup/native-pause defects as explicit observations.