You correctly diagnosed: the mini bar was still visible underneath
the full player, and that's also why the bottom controls overflowed
by 45px (the shell's mini bar was eating the bottom 88dp).
Move /now-playing OUT of the ShellRoute and up to a top-level GoRoute.
Now pushing /now-playing unmounts the shell entirely — no mini bar
underneath, no fight for the bottom strip. The slide-up transition
still feels right because the shell stays painted for the duration of
the animation (so during the transition both are briefly visible, as
you noted is fine).
Drop the hideMini conditional in _ShellWithPlayerBar — no longer
needed since the shell isn't even built when the full player is on
top. Recovering the 88dp also resolves the bottom-controls overflow
without needing to shrink the layout.
bvandeusen
59427bcf2f