* fix(playback): keep browsed server when queue plays elsewhere
Lucky Mix on a non-playback server now clears the old queue and pins
the active server before building. Now Playing metadata uses
apiForServer against the queue server instead of forcing
ensurePlaybackServerActive on every activeServerId change.
* docs: note PR #768 in CHANGELOG and settings credits
* fix(now-playing): gate AudioMuse similar artists on playback server
Match getArtistInfoForServer credentials: when browsing another server
while the queue plays elsewhere, similar-artist count follows the queue
server's AudioMuse flag, not the browsed server.
cucadmuh