List channel videos
Lists videos from a specified YouTube channel. This action primarily uses the playlistItems.list endpoint with the channel's uploads playlist, which is the recommended approach by YouTube. The uploads playlist ID is obtained by fetching the channel resource via the Channels API and extracting the playlist ID from contentDetails.relatedPlaylists.uploads field. If the uploads playlist returns a 404 error (which can happen due to a known YouTube API bug where the returned playlist ID doesn't actually exist), the action automatically falls back to the search.list endpoint to retrieve channel videos. Note that the search fallback has higher quota cost (100 units vs 1 unit) and is limited to 500 results. If a channel exists but has no uploads playlist (e.g., brand accounts, channels with all videos deleted, or channels that haven't uploaded any public content), an empty result set is returned instead of an error.