Two R8 S5 (player big-view control-bar) follow-ups:
- Modal now portals into `document.fullscreenElement ?? document.body` (reactive), the
same fullscreen-aware root the popover platform uses. A node under <body> is painted
beneath whatever holds the fullscreen lock, so the download dialog — a Modal, opened
from the player's control bar — would open invisibly in true fullscreen. With that
fixed, the `!isFullscreen` guard on the player's DownloadButton is dropped, so download
joins add-to-playlist as working in true fullscreen. (Every Modal is now fullscreen-
aware; the fix is at the primitive, not the call site.)
- The queue transport cluster (prev / counter / next + auto-advance + loop toggles) was
duplicated inline in two places — the modal queue bar and the big-view docked control
bar — with identical logic and only theme + label-visibility differing. Extracted a
`<PlayerTransportControls variant="modal"|"docked">`; a mode/icon change now lands once.
Behaviour-preserving (the docked bar's trailing divider and the wrapper rows stay at the
call sites). Note the modal variant keeps its `bg-accent/15` active tint, which is a
latent no-op under Tailwind v3's hex --accent — left as-is for R10 S0's styling audit.
Gate green (tsc/eslint/76 vitest). Device-UAT'd in real Chrome: transport controls render
correctly in both the modal queue bar and the docked bar; the download button now shows in
true fullscreen and its dialog portals into the fullscreen stage, fully visible and
centered. No console errors.