The cached-source skip only covered single track clicks; pressing Play on
an already-streamed album still resolved from scratch, and the background
album fill searched for every remaining track it appended. Three closures:
Play-album first asks the memory for every track of the record, and when
all of them are still byte-complete in the cache it queues the whole album
from memory — no search, no popup, playable offline. One unknown track
falls through to the resolver as before.
The resolver's own queue build now remembers EVERY track of the folder it
picked, not just the one that plays — one album resolve teaches the whole
record, so the next press of Play skips straight to the cache once the
files have finished arriving.
The background fill checks the memory before searching for each appended
track, and remembers what it appends, so a record that has streamed before
extends its queue instantly instead of running one 7-second search per
remaining track.
Verified live: the remembered track went from click to playing in 114ms
with the resolver never activating.