A track with no art of its own is served its album's, so hydration copies the
album's hash onto the track record. When an album resolution changed, the worker
broadcast only an `album` refresh, leaving song and now-playing surfaces holding
the previous hash-suffixed URL until something else refetched them.
Pair the album refresh with a song one. The dependent id list is unbounded — an
album has arbitrarily many tracks and a drained batch arbitrarily many albums —
so this refreshes the resource as a whole via the protocol's existing wildcard
rather than enumerating ids.
Reported by Codex on #5847.
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