Swiping back in thread should go back to main forum/media channel

CR: Version 2026.10.100, Beta 7, Channel Beta, Build 2710, Android 16 (arm64), Device Google Pixel 9a, Locale en-US, Push fcm, Flutter 3.47.7, Dart 3.13.5 I would however argue that this should only apply to threads, forum posts, and media posts when accessed through their parent channel. If you go to a thread, forum post, or media post directly from the channel list, swiping right to go back or pressing back should just take you back to the channel list since that's where you were before.