Removes the metadata argument from `WatchHistoryService.publishView` and cleans up the associated caching and resolution logic in `watchHistory.js` and `watchHistoryFeed.js`. Deletes `js/watchHistoryMetadata.js` as it is no longer used.
This simplification ensures watch history strictly manages pointers and timestamps, leaving metadata resolution to higher-level consumers. It also reduces the payload size and complexity of persisted history records.
Tests have been updated to reflect the API changes.
google-labs-jules[bot]